Inhibitors of the renal outer medullary potassium channel

ABSTRACT

The present invention provides compounds of Formula I 
                         
and the pharmaceutically acceptable salts thereof, which are inhibitors of the ROMK (Kir1.1) channel. The compounds may be used as diuretic and/or natriuretic agents and for the therapy and prophylaxis of medical conditions including cardiovascular diseases such as hypertension, heart failure and conditions associated with excessive salt and water retention.

BACKGROUND OF THE INVENTION

The Renal Outer Medullary Potassium (ROMK) channel (Kir1.1) (see e.g.,Ho, K., et al., Cloning and expression of an inwardly rectifyingATP-regulated potassium channel, Nature, 1993, 362(6415): p. 31-8.1, 2;and Shuck, M. E., et al., Cloning and characterization of multiple formsof the human kidney ROM-K potassium channel, J Biol Chem, 1994, 269(39):p. 24261-70) is a member of the inward rectifier family of potassiumchannels expressed in two regions of the kidney: thick ascending loop ofHenle (TALH) and cortical collecting duct (CCD) (see Hebert, S. C., etal., Molecular diversity and regulation of renal potassium channels,Physiol Rev, 2005, 85(1): p. 319-713). At the TALH, ROMK participates inpotassium recycling across the luminal membrane which is critical forthe function of the Na⁺/K⁺/2Cl⁻ co-transporter, the rate-determiningstep for salt reuptake in this part of the nephron. At the CCD, ROMKprovides a pathway for potassium secretion that is tightly coupled tosodium uptake through the amiloride-sensitive sodium channel (seeReinalter, S. C., et al., Pharmacotyping of hypokalaemic salt-losingtubular disorders, Acta Physiol Scand, 2004, 181(4): p. 513-21; andWang, W., Renal potassium channels: recent developments, Curr OpinNephrol Hypertens, 2004, 13(5): p. 549-55). Selective inhibitors of theROMK channel (also referred to herein as inhibitors of ROMK or ROMKinhibitors) are expected to represent novel diuretics for the treatmentof hypertension and other conditions where treatment with a diureticwould be beneficial with potentially reduced liabilities (i.e., hypo- orhyperkalemia, new onset of diabetes, dyslipidemia) over the currentlyused clinical agents (see Lifton, R. P., A. G. Gharavi, and D. S.Geller, Molecular mechanisms of human hypertension, Cell, 2001, 104(4):p. 545-56). Human genetics (Ji, W., et al., Rare independent mutationsin renal salt handling genes contribute to blood pressure variation, NatGenet, 2008, 40(5): p. 592-9; and Tobin, M. D., et al., Common variantsin genes underlying monogenic hypertension and hypotension and bloodpressure in the general population, Hypertension, 2008, 51(6): p.1658-64) and genetic ablation of ROMK in rodents (see Lorenz, J. N., etal., Impaired renal NaCl absorption in mice lacking the ROMK potassiumchannel, a model for type II Bartter's syndrome, J Biol Chem, 2002,277(40): p. 37871-80 and Lu, M., et al., Absence of small conductance K+channel (SK) activity in apical membranes of thick ascending limb andcortical collecting duct in ROMK (Bartter's) knockout mice, J Biol Chem,2002, 277(40): p. 37881-7) support these expectations. To our knowledge,the first publicly disclosed small molecule selective inhibitors ofROMK, including VU590, were reported from work done at VanderbiltUniversity as described in Lewis, L. M., et al., High-ThroughputScreening Reveals a Small-Molecule Inhibitor of the Renal OuterMedullary Potassium Channel and Kir7.1, Mol Pharmacol, 2009, 76(5): p.1094-1103. The compound VU591 was later reported in Bhave, G. et al.,Development of a Selective Small-Molecule Inhibitor of Kir1.1, the RenalOuter Medullary Potassium Channel, Mol Pharmacol, 2011, 79(1), p. 42-50,the text of which states that “ROMK (Kir1.1), is a putative drug targetfor a novel class of loop diuretics that would lower blood pressurewithout causing hypokalemia.”

Patent application publication number WO2010/129379, published Nov. 11,2010 having common representative Merck Sharp & Dohme Corp., (alsopublished as US2010/0286123 on same date), describes ROMK inhibitorshaving the generic formula:

and, e.g., an embodiment

wherein R⁵ and R⁶ are independently —H, —C₁₋₆ alkyl, —C₃₋₆ cycloalkyl,—CF₃, —CHF₂, —CH₂F or —CH₂OH; X is —H, —OH, —OC₁₋₃alkyl, —F, oxo, NH₂ or—CH₃; and X¹ is —H or —CH₃.

Patent application publication number WO2012/058134, published May 3,2012, having common representative Merck Sharp & Dohme Corp., describesROMK inhibitors having the generic formula:

wherein A and B are mono and/or bicyclic aromatic groups; R² is —H,—C₁₋₆ alkyl, —C₃₋₆ cycloalkyl, CF₃, —CH₂OH, or —CO₂R, or R² can bejoined to R¹ or R^(10a) to form a ring; R³ is —H, —C₁₋₆ alkyl, —C₃₋₆cycloalkyl, —OH, —F, —OC₁₋₃ alkyl, or —CH₂OH, or R³ can be joined toR^(10b) to form a ring.

Patent application publication number WO2012/058116, published May 3,2012, having common representative Merck Sharp & Dohme Corp., describesROMK inhibitors having the generic formula:

and, e.g., an embodiment

wherein R⁵ and R⁶ are independently —H, —C₁₋₆ alkyl or —C(O)OC₁₋₃alkyl;and X, X¹, Y and Y¹ are independently H or —C₁₋₆alkyl; or Y¹ can bejoined together with Z² to form a fused ring system.

However, continuing discovery of selective small molecule inhibitors ofROMK is still needed for the development of new treatments forhypertension, heart failure, edematous states and related disorders. Thecompounds of Formula I and salts thereof of this invention are selectiveinhibitors of the ROMK channel and could be used for the treatment ofhypertension, heart failure and other conditions where treatment with adiuretic or natriuretic would be beneficial.

SUMMARY OF THE INVENTION

The present invention provides compounds of Formula I

and the pharmaceutically acceptable salts thereof. The compounds ofFormula I are inhibitors of the ROMK (Kir1.1) channel. As a result, thecompounds of Formula I could be used in methods of treatment, inhibitionor amelioration of one or more disease states that could benefit frominhibition of ROMK. The compounds of this invention could be used inmethods of treatment which comprise administering a therapeutically orprophylactically effective amount of a compound of Formula I to apatient in need of a diuretic and/or natriuretic agent. Therefore, thecompounds of Formula I could be valuable pharmaceutically activecompounds for the therapy, prophylaxis or both of medical conditions,including, but not limited to, cardiovascular diseases such ashypertension and heart failure as well as chronic kidney disease, andconditions associated with excessive salt and water retention. Thecompounds of this invention could further be used in combination withother therapeutically effective agents, including but not limited to,other drugs which are useful for the treatment of hypertension, heartfailure and conditions associated with excessive salt and waterretention. The invention furthermore relates to processes for preparingcompounds of Formula I, and pharmaceutical compositions which comprisecompounds of Formula I. These and other aspects of the invention will beevident from the description contained herein.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to compounds having structural FormulaI:

or a pharmaceutically acceptable salt thereof wherein:

-   R¹— is H, halo particularly —F, —OH, or —OC₁₋₃alkyl particularly    —OCH₃;-   m is an integer selected from zero (R^(3b) is absent) and 1 (R^(3b)    is present);-   n is an integer selected from 1 or 2;-   R² is independently selected at each occurrence from —H, ═O (oxo),    —OH, —C₁₋₃alkyl or —OC₁₋₃alkyl, provided that when n is 2, then at    least one R² is —H;-   R^(3a) is —H, ═O, —C₃₋₄cycloalkyl or —C₁₋₃alkyl optionally    substituted with —OCH₃ or 1 to 3 of —F, provided that only one of R²    or R^(3a) can be ═O,-   R^(3b) is H or —C₁₋₃alkyl, or R^(3b) is absent when R^(3a) is ═O or    when the dashed bond is a double bond or an aromatic bond;-   or R^(3a) and R^(3b) are joined together with the carbon to which    they are both attached to form cyclopropyl or cyclobutyl;-   or when n is 1, R² and R^(3a) can be joined together with the    carbons to which they are each attached to form (1) a phenyl ring    which is fused to the pyrrolidine ring, and m is zero, or (2) a    cyclopropyl ring fused to the pyrrolidine ring, and m is 1;-   R⁴ is —H or ═O;-   R⁵ is (a) —H, (b) halo, particularly —Cl or —F, (c) —C₁₋₃alkyl    optionally substituted with —O—C₁₋₃alkyl, (d) —C₃₋₆cycloalkyl or (e)    heterocycle optionally substituted with —C₁₋₃alkyl or halo,    particularly F or —Cl;-   R⁶ is —H or —C₁₋₃alkyl;-   R^(7a) is —H or —C₁₋₃alkyl optionally substituted with —OH, —OCH₃ or    1 to 3 of —F;-   R^(7b) is —H or —C₁₋₃alkyl;-   or R^(7a) and R^(7b) are joined together with the carbon to which    they are both attached to form —C₃₋₄cycloalkyl;-   R⁸ is —H, halo particularly —F, or —C₁₋₃alkyl;-   R⁹ is —H, —F, —OH, —OC₁₋₃alkyl, —CH₂OH, —NH—R¹³ or

-   R¹⁰ is —H, halo, —CN, —C₃₋₄cycloalkyl, or —C₁₋₃alkyl optionally    substituted with 1 to 3 of —F;-   or R⁹ is —O— and is joined together with R¹⁰ to represent    —CH₂—CH₂—O—;-   R¹¹ is —H, —CH₂OH, —CH₂OCH₃, or —C₁₋₃alkyl optionally substituted    with 1 to 3 of —F;-   R¹² is —H, —CH₂OH, —CH₂OCH₃, or —C₁₋₃alkyl optionally substituted    with 1 to 3 of —F;-   or R¹¹ and R¹² are joined together to represent —CH₂—CH₂,    —CH₂—N(CH₃)—CH₂— or —CH₂OCH₂—;-   R¹³ is —H, —(CH₂)₀₋₂—C₃₋₆ cycloalkyl, —(CH₂)₁₋₂—OC₃₋₆cycloalkyl,    —(CH₂)₁₋₂—OC₁₋₃alkyl, —(CH₂)₁₋₂—CN, —C(O)OC₁₋₃alkyl, —SO₂CH₃ or    —C₁₋₃alkyl optionally substituted with one to three of —F; and-   the dashed bond (“- - -”) represents a single, double or aromatic    bond, provided that    -   (A) when n is 2, then the dashed bond is a single bond and m is        1; and    -   (B) when n is 1 and        -   (i) m is 1 (which includes but is not limited to compounds            wherein R² and R^(3a) are joined to represent cyclopropyl            fused to the pyrrolidine ring), or        -   (ii) R^(3a) is ═O and m is zero,        -   then the dashed bond is a single bond; and    -   (C) when n is 1, m is zero, R² is not ═O and R^(3a) is not ═O,        then the dashed bond is        -   (i) a double bond, or        -   (ii) an aromatic bond when R² and R^(3a) are joined together            to form the phenyl ring fused to the pyrrolidine ring.

In an embodiment of this invention are compounds of Formula I havingstructural Formula II and the pharmaceutically acceptable salts thereof:

wherein n is 1 and m is 1, and each of the variables R¹, R², R^(3a),R^(3b), R⁴, R⁵, R⁶, R^(7a), R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ and all othervariables therein are as defined in Formula I.

In an embodiment of this invention are compounds of Formula I havingstructural Formula III and the pharmaceutically acceptable saltsthereof:

wherein n is 1 and m is zero, and each of the variables R¹, R², R^(3a),R⁴, R⁵, R⁶, R^(7a), R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ and all othervariables therein are as defined in Formula I, and wherein the doublebond between R² and R^(3a) represents a non-aromatic double bond, or anaromatic bond when R² and R^(3a) are joined together with the carbons towhich they are each attached to form a phenyl ring.

In an embodiment of this invention are compounds of Formula I havingstructural Formula IV and the pharmaceutically acceptable salts thereof:

wherein n is 2 and m is 1, and each of the variables R¹, R², R^(3a),R^(3b), R⁴, R⁵, R⁶, R^(7a), R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ and all othervariables therein are as defined in Formula I.

In another embodiment of this invention are compounds of Formula Ihaving structural Formula V:

or a pharmaceutically acceptable salt thereof wherein:

-   R¹ is —H, —F, —OH or —OCH₃;-   m is an integer selected from zero (R^(3b) is absent) and 1 (R^(3b)    is present);-   n is an integer selected from 1 or 2;-   R² is independently selected at each occurrence from —H, ═O (oxo),    —OH, —C₁₋₃alkyl or —OC₁₋₃alkyl, provided that when n is 2, then at    least one R² is —H;-   R^(3a) is —H, ═O, —C₃₋₄cycloalkyl or —C₁₋₃alkyl optionally    substituted with —OCH₃ or 1 to 3 of —F, provided that only one of R²    or R^(3a) can be ═O,-   R^(3b) is —H or —C₁₋₃alkyl, or R^(3b) is absent when R^(3a) is ═O or    when the dashed bond is a double bond or an aromatic bond;-   or R^(3a) and R^(3b) are joined together with the carbon to which    they are both attached to form cyclopropyl or cyclobutyl;-   or when n is 1, R² and R^(3a) can be joined together with the    carbons to which they are each attached to form (1) a phenyl ring    which is fused to the pyrrolidine ring, and m is zero, or (2) a    cyclopropyl ring fused to the pyrrolidine ring, and m is 1;-   R⁴ is —H or ═O;-   R⁵ is —H, —Cl, —F, —C₁₋₃alkyl, —C₃₋₆cycloalkyl or heterocycle    optionally substituted with —F, —Cl or —C₁₋₃ alkyl;-   R⁶ is —H or —C₁₋₃alkyl;-   R^(7a) is —H or —C₁₋₃alkyl optionally substituted with —OH, —OCH₃ or    1 to 3 of —F;-   R⁸ is —H, —F or —C₁₋₃alkyl;-   R⁹ is —H, —F, —OH, —OC₁₋₃alkyl, —CH₂OH, —NH—R¹³ or

-   R¹⁰ is —H, halo, —CN, —C₃₋₄cycloalkyl, or —C₁₋₃alkyl optionally    substituted with 1 to 3 of —F;-   or R⁹ is —O— and is joined together with R¹⁰ to represent    —CH₂—CH₂—O—;-   R¹¹ is —H, —CH₂OH, —CH₂OCH₃, or —C₁₋₃alkyl optionally substituted    with 1 to 3 of —F;-   R¹² is —H, —CH₂OH, —CH₂OCH₃, or —C₁₋₃alkyl optionally substituted    with 1 to 3 of —F;-   or R¹¹ and R¹² are joined together to represent —CH₂—CH₂—,    —CH₂—N(CH₃)—CH₂— or —CH₂OCH₂—;-   R¹³ is —H, —(CH₂)₀₋₂—C₃₋₆ cycloalkyl, —(CH₂)₁₋₂—OC₃₋₆cycloalkyl,    —(CH₂)₁₋₂—OC₁₋₃ alkyl, —(CH₂)₁₋₂—CN, —C(O)OC₁₋₃alkyl, —SO₂CH₃ or    —C₁₋₃alkyl optionally substituted with one to three of —F; and-   the dashed bond (“- - -”) represents a single, double or aromatic    bond,-   provided that when n is 2, then the dashed bond is a single bond and    m is 1, and-   when n is 1 and m is 1, then the dashed bond is a single bond, and-   when n is 1 and m is zero, then the dashed bond is    -   (a) a double bond, or    -   (b) an aromatic bond when R² and R^(3a) are joined together to        form the phenyl ring.

In another embodiment of this invention are compounds of Formula Iwherein: n is 2 and the dashed bond is a single bond and m is 1, or n is1 and the dashed bond is a single bond and m is 2, or the dashed bond isa double bond and m is 1; R¹ is —H, —F, —OH or —C₁₋₃alkyl; R⁴ is ═O; R⁵is —H or —C₁₋₃alkyl; R⁸ is —H or —C₁₋₃alkyl; R⁹ is —OH, —OC₁₋₃alkyl or—NHR¹³; R¹⁰ is as defined; R¹¹ and R¹² are —H; and all other variablesare as defined in Formula I.

In an embodiment of this invention are compounds of Formula I whereinthe dashed bond represents a double bond or an aromatic bond. FormulasII and IV depict examples of embodiments wherein the dashed bond is asingle bond.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R¹— is H or F, and more particularly it is —H.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R² is —H at each occurrence.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R^(1a) is —H, —C₁₋₃alkyl, cyclopropyl, and moreparticularly it is —H or —CH₃.

In an embodiment of this invention are compounds of Formula I, II, IV orV wherein R^(3b) is —H or —C₁₋₃alkyl, and more particularly it is —H, orR^(3b) is absent when the dashed bond is a double bond or an aromaticbond.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R⁴ is ═O.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R⁵ is (a) —H, (b) halo, and particularly —Cl or —F, (c)—C₁₋₃alkyl (d) —C₃₋₆cycloalkyl, and more particularly it is —H or —CH₃.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R⁶ is —H or —CH₃, and more particularly it is —H.

In an embodiment of this invention are compounds of Formula I, II, IIIor IV wherein R^(7a) is —H or —C₁₋₃alkyl optionally substituted with—OH, —OCH₃ or 1 to 3 of —F, and more particularly it is —H or —CH₃.

In an embodiment of this invention are compounds of Formula I, II, IIIor IV and wherein R^(7b) is —H or —C₁₋₃alkyl, and more particularly itis —H.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R⁸ is —H.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R⁹ —H, —OH, —OCH₃ or —NH₂, and particularly it is —OH.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R¹⁰ is —H, —C₁₋₃ alkyl,

-   —C₃₋₄cycloalkyl, —F, and particularly it is —CH₃.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V thereof wherein R¹¹ is —H or —C₁₋₃alkyl, and more particularlyit is —H.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R¹² is —H or —C₁₋₃ alkyl, and more particularly it is—H; or R¹¹ and R¹² are joined together to represent —CH₂—CH₂,—CH₂—N(CH₃)—CH₂— or —CH₂OCH₂—.

In an embodiment of this invention are compounds of Formula I, II, III,IV or V wherein R¹³ is —H or —C₁₋₃alkyl, and more particularly it is —H.

In Embodiment A of this invention are compounds of Formula I, II, III,IV or V wherein: R^(3a) is —H or —CH₃; R⁴ is ═O; R⁵ is —H or —CH₃;R^(7a) is —H or —CH₃; R⁹ is —H, —OH, —OCH₃ or —NH₂, and particularly itis —OH; and R¹⁰ is —H or —CH₃, and particularly it is —CH₃. In a classthereof are compounds of Embodiment A, referred to as Embodiment B,wherein R¹ is —H; R² is —H at each occurrence; R^(3b) is —H (forcompounds of Formula I, II or IV); R⁶ is —H; R⁸ is —H; R¹¹ is —H; andR¹² is —H.

All structural Formulas and embodiments thereof described herein includethe pharmaceutically acceptable salts of the compounds defined therein.

As used herein except if noted otherwise, “alkyl” is intended to includeboth branched- and straight-chain saturated aliphatic hydrocarbon groupshaving the specified number of carbon atoms. Commonly used abbreviationsfor alkyl groups are used throughout the specification. For example theterm “C₁₋₆ alkyl” (or “C₁-C₆ alkyl”), means linear or branched chainalkyl groups, including all isomers, having the specified number ofcarbon atoms and includes all of the hexyl and pentyl isomers as well asn-, iso-, sec- and tert-butyl (butyl, s-butyl, i-butyl, t-butyl;Bu=butyl), n- and i-propyl (Pr=propyl), ethyl (Et) and methyl (Me).“Cycloalkyl” is a cyclized alkyl ring having the indicated number ofcarbon atoms. Examples of cycloalkyl include cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl.

-   -   “Halo” means —F, —Cl, —Br, or —I.    -   “Heterocycle” is intended to include pyridyl (all isomers),        pyrazinyl, pyridazinyl or pyrimidinyl.

As is well-known in the art, the term “double bond” refers to a covalentbond where two pairs of electrons are shared between two atoms. Theconcept of aromaticity is likewise well-known in the art, as exemplifiedby benzene and phenyl which are commonly drawn as having 3 alternatingdouble bonds, but may also be considered as having carbon-carbon bondswhich are each a hybrid of a single bond and a double bond. As usedherein, an “aromatic bond” refers to the aromatic nature of the doublebond between —C(R²)— and —C(R^(3a))— when R² and R^(3a) are joinedtogether to form a phenyl ring fused to the pyrrolidinyl ring as definedin Formulas I, III and V.

Unless expressly depicted or described otherwise, variables depicted ina structural formula with a “floating” bond, such as R⁸, are permittedon any available carbon atom in the ring to which the variable isattached.

The compounds of Formula I may have one or more chiral (asymmetric)centers. The present invention encompasses all stereoisomeric forms ofthe compounds of Formula I. Centers of asymmetry that are present in thecompounds of Formula I can all independently of one another have (R) or(S) configuration. When bonds to a chiral carbon are depicted asstraight lines in the structural Formulas of the invention, or when acompound name is recited without an (R) or (S) chiral designation for achiral carbon, it is understood that both the (R) and (S) configurationsof each such chiral carbon, and hence each enantiomer or diastereomerand mixtures thereof, are embraced within the Formula or by the name.The production of specific stereoisomers or mixtures thereof may beidentified in the Examples where such stereoisomers or mixtures wereobtained, but this in no way limits the inclusion of all stereoisomersand mixtures thereof from being within the scope of this invention.

The invention includes all possible enantiomers and diastereomers andmixtures of two or more stereoisomers, for example mixtures ofenantiomers and/or diastereomers, in all ratios. Thus, enantiomers are asubject of the invention in enantiomerically pure form, both aslevorotatory and as dextrorotatory antipodes, in the form of racematesand in the form of mixtures of the two enantiomers in all ratios. In thecase of a cistrans isomerism the invention includes both the cis formand the trans form as well as mixtures of these forms in all ratios. Thepreparation of individual stereoisomers can be carried out, if desired,by separation of a mixture by customary methods, for example bychromatography or crystallization, by the use of stereochemicallyuniform starting materials for the synthesis or by stereoselectivesynthesis. Optionally a derivatization can be carried out before aseparation of stereoisomers. The separation of a mixture ofstereoisomers can be carried out at an intermediate step during thesynthesis of a compound of Formula I or it can be done on a finalracemic product. Absolute stereochemistry may be determined by X-raycrystallography of crystalline products or crystalline intermediateswhich are derivatized, if necessary, with a reagent containing astereogenic center of known configuration. Alternatively, absolutestereochemistry may be determined by Vibrational Circular Dichroism(VCD) spectroscopy analysis. Where compounds of this invention arecapable of tautomerization, all individual tautomers as well as mixturesthereof are included in the scope of this invention. The presentinvention includes all such isomers, as well as salts, solvates (whichincludes hydrates) and solvated salts of such racemates, enantiomers,diastereomers and tautomers and mixtures thereof.

Reference to the compounds of Formula I herein encompasses the compoundsof Formulas I, II, III, IV and V and all embodiments thereof. Referenceto the compounds of this invention as those of a specific formula orembodiment, e.g., Formula I, II, III, IV or V or embodiments thereof, orany other generic structural formula or specific compound described orclaimed herein, is intended to encompass the specific compound orcompounds falling within the scope of the Formula or embodiment,including salts thereof, particularly pharmaceutically acceptable salts,solvates (including hydrates) of such compounds and solvated salt formsthereof, where such forms are possible, unless specified otherwise.

In the compounds of Formula I, the atoms may exhibit their naturalisotopic abundances, or one or more of the atoms may be artificiallyenriched in a particular isotope having the same atomic number, but anatomic mass or mass number different from the atomic mass or mass numberpredominantly found in nature. The present invention is meant to includeall suitable isotopic variations of the compounds of Formula I. Forexample, different isotopic forms of hydrogen (H) include protium (¹H)and deuterium (²H). Protium is the predominant hydrogen isotope found innature. Enriching for deuterium may afford certain therapeuticadvantages, such as increasing in vivo half-life or reducing dosagerequirements, or may provide a compound useful as a standard forcharacterization of biological samples. Isotopically-enriched compoundswithin Formula I can be prepared without undue experimentation byconventional techniques well known to those skilled in the art or byprocesses analogous to those described in the Schemes and Examplesherein using appropriate isotopically-enriched reagents and/orintermediates.

When the compounds of Formula I contain one or more acidic or basicgroups the invention also includes the corresponding pharmaceuticallyacceptable salts. Thus, the compounds of Formula I which contain acidicgroups can be used according to the invention as, for example but notlimited to, alkali metal salts, alkaline earth metal salts or asammonium salts. Examples of such salts include but are not limited tosodium salts, potassium salts, calcium salts, magnesium salts or saltswith ammonia or organic amines such as, for example, ethylamine,ethanolamine, triethanolamine or amino acids. Compounds of Formula Iwhich contain one or more basic groups, i.e. groups which can beprotonated, can be used according to the invention in the form of theiracid addition salts with inorganic or organic acids as, for example butnot limited to, salts with hydrogen chloride, hydrogen bromide,phosphoric acid, sulfuric acid, nitric acid, benzenesulfonic acid,methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonicacids, oxalic acid, acetic acid, trifluoroacetic acid, tartaric acid,lactic acid, salicylic acid, benzoic acid, formic acid, propionic acid,pivalic acid, diethylacetic acid, malonic acid, succinic acid, pimelicacid, fumaric acid, maleic acid, malic acid, sulfaminic acid,phenylpropionic acid, gluconic acid, ascorbic acid, isonicotinic acid,citric acid, adipic acid, etc. If the compounds of Formula Isimultaneously contain acidic and basic groups in the molecule theinvention also includes, in addition to the salt forms mentioned, innersalts or betaines (zwitterions). Salts can be obtained from thecompounds of Formula I by customary methods which are known to theperson skilled in the art, for example by combination with an organic orinorganic acid or base in a solvent or dispersant, or by anion exchangeor cation exchange from other salts. The present invention also includesall salts of the compounds of Formula I which, owing to lowphysiological compatibility, are not directly suitable for use inpharmaceuticals but which can be used, for example, as intermediates forchemical reactions or for the preparation of pharmaceutically acceptablesalts.

Furthermore, compounds of the present invention may exist in amorphousform and/or one or more crystalline forms, and as such all amorphous andcrystalline forms and mixtures thereof of the compounds of Formula I areintended to be included within the scope of the present invention. Inaddition, some of the compounds of the instant invention may formsolvates with water (i.e., a hydrate) or common organic solvents. Suchsolvates and hydrates, particularly the pharmaceutically acceptablesolvates and hydrates, of the instant compounds are likewise encompassedwithin the scope of this invention, along with un-solvated and anhydrousforms.

Any pharmaceutically acceptable pro-drug modification of a compound ofthis invention which results in conversion in vivo to a compound withinthe scope of this invention is also within the scope of this invention.For example, esters can optionally be made by esterification of anavailable carboxylic acid group or by formation of an ester on anavailable hydroxy group in a compound. Similarly, labile amides can bemade. Pharmaceutically acceptable esters or amides of the compounds ofthis invention may be prepared to act as pro-drugs which can behydrolyzed back to an acid (or —COO— depending on the pH of the fluid ortissue where conversion takes place) or hydroxy form particularly invivo and as such are encompassed within the scope of this invention.Examples of pharmaceutically acceptable pro-drug modifications include,but are not limited to, —C₁₋₆alkyl esters and —C₁₋₆alkyl substitutedwith phenyl esters.

Accordingly, the compounds within the generic structural formulas,embodiments and specific compounds described and claimed hereinencompass salts, all possible stereoisomers and tautomers, physicalforms (e.g., amorphous and crystalline forms), solvate and hydrate formsthereof and any combination of these forms, as well as the saltsthereof, pro-drug forms thereof, and salts of pro-drug forms thereof,where such forms are possible unless specified otherwise.

The compounds of Formula I according to the invention are inhibitors ofROMK, and therefore could be used as diuretic and/or natriuretic agents.ROMK inhibitors may be used to help to increase urination and increaseurine volume and also to prevent or reduce reabsorption of sodium in thekidneys leading to increased excretion of sodium and water. Therefore,the compounds could be used for treatment or prophylaxis or both ofdisorders that benefit from increased excretion of water and sodium fromthe body. Accordingly, the compounds of this invention could be used ina method for inhibiting ROMK comprising administering a compound ofFormula I in a ROMK-inhibitory effective amount to a patient in needthereof. This also encompasses the use of the compounds for inhibitingROMK in a patient comprising administering a compound of claim 1 in atherapeutically effective amount to a patient in need of diueresis,natriuresis or both. The inhibition of ROMK by the compounds of FormulaI can be examined, for example, in the Thallium Flux Assay and/orElectrophysiology Assay described below. Moreover, this invention alsorelates to the use of the compounds of Formula I or salts thereof tovalidate in vitro assays, for example but not limited to the ThalliumFlux and Electrophysiology Assays described herein.

The compounds of this invention could be used in a method for causingdiuresis, natriuresis or both, comprising administering a compound ofFormula I in a therapeutically effective amount to a patient in needthereof. Therefore, the compounds of Formula I of this invention couldbe used in methods for treatment of, prevention of or reduction of riskfor developing medical conditions that benefit from increased excretionof water and sodium, such as but not limited to one or more ofhypertension, such as essential hypertension (also known as primary oridiopathic hypertension) which is a form of hypertension for which nocause can be found, heart failure (which includes both acute heartfailure and chronic heart failure, the latter also known as congestiveheart failure) and/or other conditions associated with excessive saltand water retention. The compounds could also be used to treathypertension which is associated with any of several primary diseases,such as renal, pulmonary, endocrine, and vascular diseases, includingtreatment of patients with medical conditions such as heart failureand/or chronic kidney disease. Furthermore, the compounds of Formula Icould be used in methods for treatment of, prevention of or reduction ofrisk for developing one or more disorders such as pulmonaryhypertension, particularly pulmonary arterial hypertension (PAH),cardiovascular disease, edematous states, diabetes mellitus, diabetesinsipidus, post-operative volume overload, endothelial dysfunction,diastolic dysfunction, systolic dysfunction, stable and unstable anginapectoris, thromboses, restenosis, myocardial infarction, stroke, cardiacinsufficiency, pulmonary hypertonia, atherosclerosis, hepatic cirrhosis,ascitis, pre-eclampsia, cerebral edema, nephropathy, glomerulonephritis,nephrotic syndrome, acute kidney insufficiency, chronic kidneyinsufficiency (also referred to as chronic kidney disease, or moregenerally as renal impairment), acute tubular necrosis, hypercalcemia,idiopathic edema, Dent's disease, Meniere's disease, glaucoma, benignintracranial hypertension, and other conditions for which a diuretic ornatriuretic or both would have therapeutic or prophylactic benefit. Thecompounds of the invention may be administered to a patient having, orat risk of having, one or more conditions for which a diuretic ornatriuretic or both would have therapeutic or prophylactic benefit suchas those described herein.

The compounds of Formula I may potentially have reduced liabilities (forexample, hypo- or hyperkalemia, new onset of diabetes, dyslipidemia,etc.) over currently used clinical agents. Also the compounds may havereduced risk for diuretic tolerance, which can be a problem withlong-term use of loop diuretics.

In general, compounds that are ROMK inhibitors can be identified asthose compounds which, when tested, have an IC₅₀ of 5 μM or less,preferably 1 μM or less, and more preferably 0.25 μM or less, in atleast one of the following assays: 1) Thallium Flux Assay, 2)Electrophysiology Assay. These assays are described in more detailfurther below.

The dosage amount of the compound to be administered depends on theindividual case and is, as is customary, to be adapted to the individualcircumstances to achieve an optimum effect. Thus, it depends on thenature and the severity of the disorder to be treated, and also on thesex, age, weight and individual responsiveness of the human or animal tobe treated, on the efficacy and duration of action of the compoundsused, on whether the therapy is acute or chronic or prophylactic, or onwhether other active compounds are administered in addition to compoundsof Formula I. A consideration of these factors is well within thepurview of the ordinarily skilled clinician for the purpose ofdetermining the therapeutically effective or prophylactically effectivedosage amount needed to prevent, counter, or arrest the progress of thecondition. It is expected that the compound will be administeredchronically on a daily basis for a length of time appropriate to treator prevent the medical condition relevant to the patient, including acourse of therapy lasting days, months, years or the life of thepatient.

In general, a daily dose of approximately 0.001 to 100 mg/kg, preferably0.001 to 30 mg/kg, in particular 0.001 to 10 mg/kg (in each case mg perkg of bodyweight) is appropriate for administration to an adult weighingapproximately 75 kg in order to obtain the desired results. The dailydose is preferably administered in a single dose or can be divided intoseveral, for example two, three or four individual doses, and may be,for example but not limited to, 0.1 mg, 0.25 mg, 0.5 mg, 0.75 mg, 1 mg,1.25 mg, 2 mg, 2.5 mg, 5 mg, 10 mg, 20 mg, 40 mg, 50 mg, 75 mg, 100 mg,125 mg, 150 mg, 175 mg, 200 mg, etc., on a daily basis. In some cases,depending on the potency of the compound or the individual response, itmay be necessary to deviate upwards or downwards from the given dailydose. Furthermore, the compound may be formulated for immediate ormodified release such as extended or controlled release.

The term “patient” includes animals, preferably mammals and especiallyhumans, who use the instant active agents for the prophylaxis ortreatment of a medical condition. Administering of the drug to thepatient includes both self-administration and administration to thepatient by another person. The patient may be in need of treatment foran existing disease or medical condition, or may desire prophylactictreatment to prevent or reduce the risk for developing said disease ormedical condition or developing long-term complications from a diseaseor medical condition.

The term therapeutically effective amount is intended to mean thatamount of a drug or pharmaceutical agent that will elicit the biologicalor medical response of a tissue, a system, animal or human that is beingsought by a researcher, veterinarian, medical doctor or other clinician.A prophylactically effective amount is intended to mean that amount of apharmaceutical drug that will prevent or reduce the risk of occurrenceof the biological or medical event that is sought to be prevented in atissue, a system, animal or human by a researcher, veterinarian, medicaldoctor or other clinician. The terms “preventing,” “prevention,”“prophylactic” and derivatives of these terms as used herein refer toadministering a compound to a patient before the onset of clinicalsymptoms of a condition not yet present in the patient. It is understoodthat a specific daily dosage amount can simultaneously be both atherapeutically effective amount, e.g., for treatment of hypertension,and a prophylactically effective amount, e.g., for prevention orreduction of risk of myocardial infarction or prevention or reduction ofrisk for complications related to hypertension.

In the methods of treatment of this invention, the ROMK inhibitors maybe administered via any suitable route of administration such as, forexample, orally, parenterally, or rectally in dosage unit formulationscontaining conventional non-toxic pharmaceutically acceptable carriers,adjuvants and vehicles. The term parenteral as used herein includessubcutaneous injections, intravenous (IV), intramuscular, intrasternalinjection or infusion techniques. Oral formulations are preferred fortreatment of chronic indications such as hypertension or chronic heartfailure, particularly solid oral dosage units such as pills, tablets orcapsules, and more particularly tablets. IV dosing is preferred foracute treatment, for example for the treatment of acute heart failure.

This invention also provides pharmaceutical compositions comprised of acompound of Formula I and a pharmaceutically acceptable carrier which iscomprised of one or more excipients or additives. An excipient oradditive is an inert substance used to formulate the active drugingredient. For oral use, the pharmaceutical compositions of thisinvention containing the active ingredient may be in forms such aspills, tablets, troches, lozenges, aqueous or oily suspensions,dispersible powders or granules, emulsions, hard or soft capsules, orsyrups or elixirs. Compositions intended for oral use may be preparedaccording to any method known to the art for the manufacture ofpharmaceutical compositions. Tablets contain the active ingredient inadmixture with non-toxic pharmaceutically acceptable excipients whichare suitable for the manufacture of tablets. The excipients may be forexample, inert diluents, such as calcium carbonate, sodium carbonate,lactose, mannitol, calcium phosphate or sodium phosphate; granulatingand disintegrating agents, for example, corn starch, or alginic acid;binding agents, for example starch, gelatin or acacia, and lubricatingagents, for example, magnesium stearate, stearic acid or talc.

Pharmaceutical compositions may also contain other customary additives,for example but not limited to, wetting agents, stabilizers,emulsifiers, dispersants, preservatives, sweeteners, colorants,flavorings, aromatizers, thickeners, buffer substances, solvents,solubilizers, agents for achieving a depot effect, salts for alteringthe osmotic pressure, coating agents or antioxidants. Oralimmediate-release and time-controlled release dosage forms may beemployed, as well as enterically coated oral dosage forms. Tablets maybe uncoated or they may be coated by known techniques for aestheticpurposes, to mask taste or for other reasons. Coatings can also be usedto delay disintegration and absorption in the gastrointestinal tract andthereby provide a sustained action over a longer period. For example, atime delay material such as glyceryl monostearate or glyceryl distearatemay be employed.

Formulations for oral use may also be presented as hard gelatin capsuleswherein the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredients is mixed with water ormiscible solvents such as propylene glycol, PEGs and ethanol, or an oilmedium, for example peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions contain the active material in admixture withexcipients suitable for the manufacture of aqueous suspensions. Oilysuspensions may be formulated by suspending the active ingredient in avegetable oil, for example arachis oil, olive oil, sesame oil or coconutoil, or in mineral oil such as liquid paraffin. The oily suspensions maycontain a thickening agent, for example beeswax, hard paraffin or cetylalcohol. Sweetening agents and flavoring agents may be added to providea palatable oral preparation. These compositions may be preserved by theaddition of an anti-oxidant such as ascorbic acid. Syrups and elixirsmay be formulated with sweetening agents, for example glycerol,propylene glycol, sorbitol or sucrose.

The instant invention also encompasses a process for preparing apharmaceutical composition comprising combining a compound of Formula Iwith a pharmaceutically acceptable carrier. Also encompassed is thepharmaceutical composition which is made by combining a compound ofFormula I with a pharmaceutically acceptable carrier. Furthermore, atherapeutically effective amount of a compound of this invention can beused for the preparation of a medicament useful for inhibiting ROMK, forcausing diuresis and/or natriuresis, and/or for treating, preventing orreducing the risk for any of the medical conditions described herein, indosage amounts described herein.

The amount of active compound of Formula I and/or its pharmaceuticallyacceptable salts in the pharmaceutical composition may be, for examplebut not limited to, from about 0.1 mg to 1 g, particularly 0.1 mg toabout 200 mg, more particularly from about 0.1 mg to about 100 mg, andeven more particularly from about 0.1 to about 50 mg, per dose on a freeacid/free base weight basis, but depending on the type of thepharmaceutical composition, potency of the active ingredient and/or themedical condition being treated, it could also be lower or higher.Pharmaceutical compositions usually comprise about 0.5 to about 90percent by weight of the active compound on a free acid/free base weightbasis.

The compounds of Formula I inhibit ROMK. Due to this property, apartfrom use as pharmaceutically active compounds in human medicine andveterinary medicine, they can also be employed as a scientific tool oras aid for biochemical investigations in which such an effect on ROMK isintended, and also for diagnostic purposes, for example in the in vitrodiagnosis of cell samples or tissue samples. The compounds of Formula Ican also be employed as intermediates for the preparation of otherpharmaceutically active compounds.

One or more additional pharmacologically active agents may beadministered in combination with a compound of Formula I. The additionalactive agent (or agents) is intended to mean a medicinal compound thatis different from the compound of Formula I, and which is apharmaceutically active agent (or agents) that is active in the body,including pro-drugs, for example esterified forms, that convert topharmaceutically active form after administration, and also includesfree-acid, free-base and pharmaceutically acceptable salts of saidadditional active agents when such forms are sold commercially or areotherwise chemically possible. Generally, any suitable additional activeagent or agents, including but not limited to anti-hypertensive agents,additional diuretics, anti-atherosclerotic agents such as a lipidmodifying compound, anti-diabetic agents and/or anti-obesity agents maybe used in any combination with the compound of Formula I in a singledosage formulation (a fixed dose drug combination), or may beadministered to the patient in one or more separate dosage formulationswhich allows for concurrent or sequential administration of the activeagents (co-administration of the separate active agents). Examples ofthe one or more additional active agents which may be employed includebut are not limited to thiazide-like diuretics, e.g.,hydrochlorothiazide (HCTZ or HCT); angiotensin converting enzymeinhibitors (e.g, alacepril, benazepril, captopril, ceronapril,cilazapril, delapril, enalapril, enalaprilat, fosinopril, imidapril,lisinopril, moveltipril, perindopril, quinapril, ramipril, spirapril,temocapril, or trandolapril); dual inhibitors of angiotensin convertingenzyme (ACE) and neutral endopeptidase (NEP) such as omapatrilat,sampatrilat and fasidotril; angiotensin II receptor antagonists, alsoknown as angiotensin receptor blockers or ARBs, which may be infree-base, free-acid, salt or pro-drug form, such as azilsartan, e.g.,azilsartan medoxomil potassium (EDARBI®), candesartan, e.g., candesartancilexetil (ATACAND®), eprosartan, e.g., eprosartan mesylate (TEVETAN®),irbesartan (AVAPRO®), losartan, e.g., losartan potassium (COZAAR®),olmesartan, e.g, olmesartan medoximil (BENICAR®), telmisartan(MICARDIS®), valsartan (DIOVAN®), and any of these drugs used incombination with a thiazide-like diuretic such as hydrochlorothiazide(e.g., HYZAAR®, DIOVAN HCT®, ATACAND HCT®), etc.); potassium sparingdiuretics such as amiloride HCl, spironolactone, epleranone,triamterene, each with or without HCTZ; carbonic anhydrase inhibitors,such as acetazolamide; neutral endopeptidase inhibitors (e.g., thiorphanand phosphoramidon); aldosterone antagonists; aldosterone synthaseinhibitors; renin inhibitors (e.g. urea derivatives of di- andtri-peptides (See U.S. Pat. No. 5,116,835), amino acids and derivatives(U.S. Pat. Nos. 5,095,119 and 5,104,869), amino acid chains linked bynon-peptidic bonds (U.S. Pat. No. 5,114,937), di- and tri-peptidederivatives (U.S. Pat. No. 5,106,835), peptidyl amino diols (U.S. Pat.Nos. 5,063,208 and 4,845,079) and peptidyl beta-aminoacyl aminodiolcarbamates (U.S. Pat. No. 5,089,471); also, a variety of other peptideanalogs as disclosed in the following U.S. Pat. Nos. 5,071,837;5,064,965; 5,063,207; 5,036,054; 5,036,053; 5,034,512 and 4,894,437, andsmall molecule renin inhibitors (including diol sulfonamides andsulfinyls (U.S. Pat. No. 5,098,924), N-morpholino derivatives (U.S. Pat.No. 5,055,466), N-heterocyclic alcohols (U.S. Pat. No. 4,885,292) andpyrolimidazolones (U.S. Pat. No. 5,075,451); also, pepstatin derivatives(U.S. Pat. No. 4,980,283) and fluoro- and chloro-derivatives ofstatone-containing peptides (U.S. Pat. No. 5,066,643); enalkrein; RO42-5892; A 65317; CP 80794; ES1005; ES 8891; SQ 34017; aliskiren(2(S),4(S),5(S),7(S)—N-(2-carbamoyl-2-methylpropyl)-5-amino-4-hydroxy-2,7-diisopropyl-8-[4-methoxy-3-(3-methoxypropoxy)-phenyl]-octanamidhemifumarate) SPP600, SPP630 and SPP635); endothelin receptorantagonists; vasodilators (e.g. nitroprusside); calcium channel blockers(e.g., amlodipine, nifedipine, verapamil, diltiazem, felodipine,gallopamil, niludipine, nimodipine, nicardipine, bepridil, nisoldipine);potassium channel activators (e.g., nicorandil, pinacidil, cromakalim,minoxidil, aprilkalim, loprazolam); sympatholitics; beta-adrenergicblocking drugs (e.g., acebutolol, atenolol, betaxolol, bisoprolol,carvedilol, metoprolol, metoprolol tartate, nadolol, propranolol,sotalol, timolol); alpha adrenergic blocking drugs (e.g., doxazocin,prazocin or alpha methyldopa); central alpha adrenergic agonists;peripheral vasodilators (e.g. hydralazine); nitrates or nitric oxidedonating compounds, e.g. isosorbide mononitrate; lipid lowering agents,e.g., HMG-CoA reductase inhibitors such as simvastatin and lovastatinwhich are marketed as ZOCOR® and MEVACOR® in lactone pro-drug form andfunction as inhibitors after administration, and pharmaceuticallyacceptable salts of dihydroxy open ring acid HMG-CoA reductaseinhibitors such as atorvastatin (particularly the calcium salt sold inLIPITOR®), rosuvastatin (particularly the calcium salt sold inCRESTOR®), pravastatin (particularly the sodium salt sold inPRAVACHOL®), and fluvastatin (particularly the sodium salt sold inLESCOL®); a cholesterol absorption inhibitor such as ezetimibe (ZETIA®),and ezetimibe in combination with any other lipid lowering agents suchas the HMG-CoA reductase inhibitors noted above and particularly withsimvastatin (VYTORIN®) or with atorvastatin calcium; niacin inimmediate-release or controlled release forms, and particularly niacinin combination with a DP antagonist such as laropiprant (TREDAPTIVE)and/or with an HMG-CoA reductase inhibitor; niacin receptor agonistssuch as acipimox and acifran, as well as niacin receptor partialagonists; metabolic altering agents including insulin sensitizing agentsand related compounds for the treatment of diabetes such as biguanides(e.g., metformin), meglitinides (e.g., repaglinide, nateglinide),sulfonylureas (e.g., chlorpropamide, glimepiride, glipizide, glyburide,tolazamide, tolbutamide), thiazolidinediones also referred to asglitazones (e.g., pioglitazone, rosiglitazone), alpha glucosidaseinhibitors (e.g., acarbose, miglitol), dipeptidyl peptidase inhibitors,(e.g., sitagliptin (JANUVIA®), alogliptin, vildagliptin, saxagliptin,linagliptin, dutogliptin, gemigliptin), ergot alkaloids (e.g.,bromocriptine), combination medications such as JANUMET® (sitagliptinwith metformin), and injectable diabetes medications such as exenatideand pramlintide acetate; phosphodiesterase-5 (PDE5) inhibitors such assildenafil (Revatio, Viagra), tadalafil (Clalis, Adcirca) vardenafil HCl(Levitra); or with other drugs beneficial for the prevention or thetreatment of the above-mentioned diseases including but not limited todiazoxide; and including the free-acid, free-base, and pharmaceuticallyacceptable salt forms, pro-drug forms (including but not limited toesters), and salts of pro-drugs of the above medicinal agents wherechemically possible. Trademark names of pharmaceutical drugs noted aboveare provided for exemplification of the marketed form of the activeagent(s); such pharmaceutical drugs could be used in a separate dosageform for concurrent or sequential administration with a compound ofFormula I, or the active agent(s) therein could be used in a fixed dosedrug combination including a compound of Formula I.

Several methods for preparing the compounds of this invention aredescribed in the following Schemes and Examples. Starting materials andintermediates are purchased, made from known procedures, or as otherwiseillustrated. Some frequently applied routes to the compounds of FormulaI are also described by the Schemes as follows. In some cases the orderof carrying out the steps of reaction schemes may be varied tofacilitate the reaction or to avoid unwanted reaction products. The “R”substituents in the Schemes correspond to the substituents defined inFormula I at the same positions on the structures.

Compound IA, which is substituted at the benzylic position with an OHgroup, can be prepared following the sequence detailed in Scheme 1.Coupling of epoxide 1 to spirocyclic amines 2 at elevated temperaturesleads to the formation of alcohols IA (Nomura, Y. et al. Chemical &Pharmaceutical Bulletin, 1995, 43(2), 241-6). The reaction can becarried out with conventional heating, or by heating using a microwaveapparatus. A number of solvents can be used in this reaction, forexample, ethanol and 2-propanol. Spirocyclic amines may be free bases,or they may be salts, in which case a base such as triethylamine or N;N-diisopropylethylamine may be added. Note that when enantiopure chiralepoxides are employed (such as (R)-1 in Scheme 1) epoxide opening occurswith retention of stereochemistry in the benzylic position andindividual isomer (R)-IA may be obtained (and if the (S)-epoxide isemployed the alcohol produced will have the opposite stereochemistry tothat shown). Alternatively, chiral HPLC separation of enantiomers ordiastereomers of IA may be performed to provide single enantiomers ordiastereomers.

Compounds of formula IB can be prepared by the sequence detailed inScheme 2. Aldhehydes or ketones 3 may be used in reductive alkylationreactions of spirocyclic amines 2 to afford ROMK inhibitors of theformula IB by using various reductive amination conditions (for exampleusing sodium cyanoborohydride, sodium triacetoxy borohydride, ortitanium tetra-isopropoxide, followed by sodium borohydride or sodiumcyanoborohydride).

The epoxides 1 (and single enantiomers (R)-1 and (S)-1) can be preparedfollowing the method detailed in Scheme 3. Treatment of 4 (where X ischloride, bromide, iodide, or trifluoromethane sulfonate) withcommercially available potassium vinyl trifluoroborate (Molander, G.;Luciana, A. Journal of Organic Chemistry, 2005, 70(10), 3950-3956) underpalladium catalyzed coupling conditions with an appropriate phosphineligand gives rise to styrene 5 (Molander, G.; Brown, A. Journal ofOrganic Chemistry, 2006, 71(26), 9681-9686). Alternatively, othermethods may be employed, for example, using vinylstannane reagents andpalladium catalysis. The resulting styrenes 5 can be converted to thecorresponding epoxides 1 under various epoxidation conditions, forexample, with mCPBA (Fringuelli, F. et al. Organic Preparations andProcedures International, 1989, 21(6), 757-761). The racemic epoxide 1can be resolved under chiral HPLC chromatography conditions to affordits enantiomers, which can be used in place of 1 according to Scheme 1.

Alternatively, enantiopure epoxides (R)-1 or (S)-1 can be prepared asshown in Scheme 4. Treatment of 4 (where X is bromide, iodide, ortrifluoromethane sulfonate) with commercial available vinyl butylether 6under palladium catalyzed conditions with a suitable ligand (for examplePd(OAc)₂, DPPP) can provide the enol ethers 7. Enol ethers may beprepared using other methods known to the chemist. Treatment of theresulting enol ethers 7 with NBS or other similar reagents affords thecorresponding bromomethyl ketones 8. These can be subjected to a varietyof asymmetric ketone reduction conditions, for example with an enzymethat can affect such a transformation with high enantioselectivity.Subsequent treatment with a base such as triethylamine leads tocyclization, affording the enantioenriched epoxides (R)-1 or (S)-1(depending upon the asymmetric reducing agent).

Aldehydes 3A may be prepared in numerous ways, with two approachesdescribed in Scheme 5. Treatment of 4 (where X is bromide, iodide, ortrifluoromethane sulfonate) with bromo(1,3-dioxolan-2-ylmethyl)zinc inthe presence of an appropriate palladium catalyst and ligand, such aspalladium(II) acetate and tri-t-butylphosphine-BF₄ complex, provides thecorresponding aryl 1,3-dioxolan-2-ylmethyl derivative 9. Then thealdehydes 3A may be obtained by treatment with HCl in the presence ofwater and an organic solvent. Alternatively, reaction of 4 (where X isbromide, iodide, or trifluoromethane sulfonate) withallyltributylstannane in the presence of palladium catalyst affords theallyl product 10. Oxidation, for example with ozone, followed bydimethyl sulfide, provides aldehydes 3A.

Spirocyclic aminofuranones 2 can be prepared as described in Scheme 6.Spirocyclic diamines or amino lactams (where R¹¹ and R¹² togetherrepresent a carbonyl group) 11, protected as appropriate (Greene, T.;Wuts, P. G. M. protective Groups in Organic Synthesis, John Wiley andSons, Inc., New York, N.Y. 1991), can be coupled to furanone triflatesor bromides 12 using a palladium catalyst and ligand, for examplepalladium acetate and 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene.Some spirocyclic diamines or amino lactams 11 described herein arecommercially available; others can prepared as described in theexperimental section below. 4-Bromofuran-2(5H)-one is commerciallyavailable; other furanones 12 can be prepared as described in theexamples below. Intermediates 13 are converted to spirocyclicaminofuranones 2 by removal of the protective group, for example,tert-butoxycarbonyl can be removed with TFA or HCl.

Spirocyclic amino lactams 11A, can be prepared in numerous ways,including those described in Scheme 7. Commercially availableaminoesters 14 can be alkylated with bromoacetonitrile 15 using a basesuch as lithium diisopropylamide to afford nitrile intermediates 16.Reduction, for example using platinum oxide and hydrogen, or RaneyNickel, produces lactams 11A. Alternatively, aminoesters may bealkylated with allyl halides 17 using a base such as lithiumdiisopropylamide to furnish allyl intermediates 18. Oxidative cleavage,employing, for example, osmium tetroxide and sodium periodate providesketones and aldehydes 19. Reductive amination with tandem lactamcyclization to 11A can be accomplished in several ways, including bytreatment with ammonium acetate and sodium cyanoborohydride in a solventsuch as methanol, as shown.

The independent synthesis of diastereomers and enantiomers or theirchromatographic separations may be achieved as known in the art byappropriate modification of the methodology disclosed herein. Theirabsolute stereochemistry may be determined by x-ray crystallography ofcrystalline products or crystalline intermediates which are derivatized,if necessary, with a reagent containing an asymmetric center of knownabsolute stereochemistry, or by vibrational circular dichroism (VCD)spectroscopy.

The subject compounds may be prepared by modification of the proceduresdisclosed in the Examples as appropriate. Starting materials arecommercially available or made by known procedures or as illustrated.The following examples are provided for the purpose of furtherillustration only and are not intended to be limitations on thedisclosed invention.

Reactions sensitive to moisture or air were performed under nitrogen orargon using anhydrous solvents and reagents. The progress of reactionswas determined by either analytical thin layer chromatography (TLC)usually performed with E. Merck pre-coated TLC plates, silica gel60E-254, layer thickness 0.25 mm or liquid chromatography-massspectrometry (LC-MS).

Typically the analytical LC-MS system used consisted of a Waters ZQplatform with electrospray ionization in positive ion detection modewith an Agilent 1100 series HPLC with autosampler. The column wasusually a Water Xterra MS C18, 3.0×50 mm, 5 μm. The flow rate was 1mL/min, and the injection volume was 10 μL. UV detection was in therange 210-400 nm. The mobile phase consisted of solvent A (water plus0.06% TFA) and solvent B (acetonitrile plus 0.05% TFA) with a gradientof 100% solvent A for 0.7 min changing to 100% solvent B over 3.75 min,maintained for 1.1 min, then reverting to 100% solvent A over 0.2 min.

Preparative HPLC purifications were usually performed using a massspectrometry directed system. Usually they were performed on a WatersChromatography Workstation configured with LC-MS System Consisting of:Waters ZQ single quad MS system with Electrospray Ionization, Waters2525 Gradient Pump, Waters 2767 Injector Collector, Waters 996 PDADetector, the MS Conditions of: 150-750 amu, Positive Electrospray,Collection Triggered by MS, and a Waters Sunfire C-18 5 micron, 30 mm(id)×100 mm column. The mobile phases consisted of mixtures ofacetonitrile (10-100%) in water containing 0.1% TFA. Flow rates weremaintained at 50 mL/min, the injection volume was 1800 μL, and the UVdetection range was 210-400 nm. Mobile phase gradients were optimizedfor the individual compounds.

Reactions performed using microwave irradiation were normally carriedout using an Emrys Optimizer manufactured by Personal Chemistry, or anInitiator manufactured by Biotage.

Concentration of solutions was carried out on a rotary evaporator underreduced pressure. Flash chromatography was usually performed using aBiotage Flash Chromatography apparatus (Dyax Corp.) on silica gel (32-63mM, 60 Å pore size) in pre-packed cartridges of the size noted. ¹H NMRspectra were acquired at 500 MHz spectrometers in CDCl₃ solutions unlessotherwise noted. Chemical shifts were reported in parts per million(ppm). Tetramethylsilane (TMS) was used as internal reference in CD₃Clsolutions, and residual CH₃OH peak or TMS was used as internal referencein CD₃OD solutions. Coupling constants (J) were reported in hertz (Hz).

Chiral analytical chromatography was usually performed on one ofChiralpak AS, Chiralpak AD, Chiralcel OD, Chiralcel IA, or Chiralcel OJcolumns (250×4.6 mm) (Daicel Chemical Industries, Ltd.) with notedpercentage of either ethanol in hexane (% EtHex) or isopropanol inheptane (% IPAHep) as isocratic solvent systems. Chiral preparativechromatography was sometimes conducted on one of Chiralpak AS, ChiralpakAD, Chiralcel OD, Ciralcel IA, or Chiralcel OJ columns (20×250 mm)(Daicel Chemical Industries, Ltd.) with desired isocratic solventsystems identified on chiral analytical chromatography or bysupercritical fluid (SFC) conditions. Alternatively, chiral preparativechromatography was by supercritical fluid (SFC) conditions using one ofChiralpak AS, Chiralpak AD-H, Chiralcel OD-H, Chiralpak IC, or ChiralcelOJ-H columns (250×21.2 mm) (Daicel Chemical Industries, Ltd.). Whereretention times are provided in the Examples and Tables, they are notintended to be a definitive characteristic of a particular compoundsince, as known to those skilled in the art, retention times will varyand the timing and/or order of peak elution may change depending on thechromatographic conditions, such as the column used, the condition ofthe column, and the solvent system and instruments used.

Concentration of solutions was generally carried out on a rotaryevaporator under reduced pressure. Flash chromatography was carried outon silica gel (230-400 mesh). NMR spectra were obtained in CDCl₃solution unless otherwise noted. Coupling constants (J) are in hertz(Hz).

Abbreviations and acronyms used herein include: —C(O)CH₃ (Ac); —OC(O)CH₃(OAc); acetic acid (AcOH; HOAc); 1-chloroethylchloroformate (ACE-Cl);2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP); t-butyloxycarbonyl(Boc or BOC); di-t-butyl dicarbonate ((BOC)₂O, Boc₂O); benzyloxycarbonyl(Cbz); Cyclopentyl methyl ether (CPME); Carbonyldiimidazole (CDI);Diethylaminosulfur trifluoride (DAST); dibenzylideneacetone (dba);1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU); 1,2-dichloroethane (DCE);dichloromethane (DCM); dimethoxyethane (DME); Diisobutylaluminiumhydride (DIBAL-H); N,N-diisopropylethylamine (DIEA, DIPEA, Hunig'sbase); di-isopropylamine (DIPA); 1,1′-bis(diphenylphosphino)ferrocene(dppf, DPPF); Dess-Martin Periodinane (DMP;1,1,1-Triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one); dimethylsulfide(DMS); dimethylsulfoxide (DMSO); N; N-dimethylformamide (DMF);4-dimethylaminopyridine (DMAP); dimethylacetamide (DMA; DMAC);1,3-Bis(diphenylphosphino)propane (DPPP); ethyl acetate (EtOAc); diethylether (ether or Et₂O); 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide(EDC, EDAC or EDCI);2-(7-Aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluroniumhexafluorophosphate (HATU); hexane (Hex); hexamethylphosphoramide(HMPA); 1-Hydroxybenzotriazole hydrate (HOBt); isopropanol (IPA);isopropyl acetate (IPAc); Potassium bis(trimethylsilyl)amide (KHMDS);lithium aluminum hydride (LAH); lithium diisopropylamide (LDA);3-chloroperoxybenzoic acid (mCPBA); methanol (MeOH); CH₃SO₂— (mesyl orMs); methane sulfonyl chloride or mesyl chloride (MsCl); methanesulfonicacid (MsOH); methyl tert-butyl ether (MTBE); nicotinamide adeninedinucleotide phosphate (NADP); N-bromo succinimide (NBS);N-chlorosuccinimide (NCS); N-iodosuccinimide (NIS);N-methylmorpholine-N-oxide (NMO); N-methyl morpholine (NMP); sodiumhoxamethyldisilazide (NaHMDS); sodium triacetoxyborohydride(NaBH(OAc)₃); Pyridinium chlorochromate (PCC); phenyl (Ph); petroleumether (PE or petrol ether); tetrakis(triphenylphosphine)palladium(Pd(PPh₃)₄); tris(dibenzylidineacetone)dipalladium (Pd₂(dba)₃);Pd(dppf)Cl₂ or PdCl₂(dppf) is1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) which may becomplexed with CH₂Cl₂; tetra-n-butylammonium fluoride (TBAF);tert-butyldimethylsilyl chloride (TBS-Cl); triethylamine (TEA);trifluoroacetic acid (TFA); —SO₂CF₃ (Tf); trifluoromethanesulfonic acid(triflic acid, TfOH); trifluoromethanesulfonic anhydride (triflicanhydride, (Tf)₂O); 2-tetrahydrofuran (THF);N,N,N′,N′-Tetramethylethylenediamine (TMEDA); p-toluenesulfonic acid(TsOH); Dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-Phos);Diethylaminodifluorosulfinium tetrafluoroborate (XtalFluor-E®);4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos). Additionalabbreviations and acronyms are: starting material (SM); round-bottomflask (RB or RBF); aqueous (aq); saturated aqueous (sat'd); saturatedaqueous sodium chloride solution (brine); medium pressure liquidchromatography (MPLC); high pressure liquid chromatography (HPLC);preparative HPLC (prep-HPLC); flash chromatography (FC); liquidchromatography (LC); supercritical fluid chromatography (SFC); thinlayer chromatography (TLC); preparative TLC (prep-TLC); mass spectrum(ms or MS); liquid chromatography-mass spectrometry (LC-MS, LCMS orLCMS); column volume (CV); room temperature (rt, r.t. or RT); hour(s) (hor hr); minute(s) (min); retention time (R_(t)); gram(s) (g);milligram(s) (mg); milliliter(s) (mL); microliter(s) (μL); millimole(mmol); volume:volume (V/V). CELITE® is a trademark name fordiatomaceous earth, and SOLKA FLOC® is a trademark name for powderedcellulose. X or x may be used to express the number of times an actionwas repeated (e.g., washed with 2×200 mL 1N HCl), or to convey adimension (e.g., the dimension of a column is 30×250 mm).

The following are representative procedures for the preparation ofintermediates used to prepare the final products described in theExamples that follow thereafter. These examples are provided for thepurpose of further illustration only and are not intended to belimitations on the disclosed invention.

It is understood that a chiral center in a compound may exist in the “S”or “R” stereoconfigurations, or as a mixture of both. In many of theexamples, compounds having a chiral center were separated into singlestereoisomers (for example, referred to as Isomer A and Isomer B, orfaster/slower eluting isomers), or each was derived synthetically from asingle isomer intermediate. Except for a defined chiral center in theparent mixture, absolute stereochemistry (R or S) of each of theseparated isomers was not determined, unless specifically notedotherwise.

Intermediates described below may be referred to herein by their numberpreceded by “I-”. For example, Intermediate 4A is shortened to I-4A.

Intermediate 1

(1-Oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde

Step A: 5-(1,3-Dioxolan-2-ylmethyl)-2-benzofuran-1(3H)-one: A three-neck5 L round bottomed flask equipped with a stir bar, firestone valve,thermocouple, condenser and heating mantle was charged with tri-t-butylphosphonium tetrafluoroborate (500 mg, 1.72 mmol), palladium (II)acetate (250 mg, 1.1 mmol) and 5-bromo-2-benzofuran-1(3H)-one (100 g,470 mmol). DMF (1.88 L) was added to the flask, and the mixture wasdegassed three times by alternating vacuum and nitrogen purge.Commercially available bromo(1,3-dioxolan-2-ylmethyl)zinc solution (1.03L, 516 mmol) was added via canula and the mixture was again degassedthree times. The mixture was then heated at 85° C. for 5 h. Analysis byHPLC-MS indicated the reaction was not complete. The mixture was stirredat 85° C. for 5 more h. The mixture was then allowed to return to roomtemperature for overnight. 2-methylTHF (2 L) and brine were added, andthe mixture was stirred for 5 min. The layers were separated and theaqueous layer was extracted again with 2-methylTHF. The organic layerswere combined, washed three times with brine (4 L each), dried overMgSO₄, filtered, and concentrated. The crude product was purified byflash chromatography (1.5 kg silica cartridge), eluting with 0-20% ethylacetate in dichloromethane to afford5-(1,3-dioxolan-2-ylmethyl)-2-benzofuran-1(3H)-one. LC-MS (IE, m/z): 221[M+1]⁺.

Step B: (1-Oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde:5-(1,3-Dioxolan-2-ylmethyl)-2-benzofuran-1(3H)-one (61 g, 280 mmol) wascombined with water (2.2 L) in a 5 L round bottomed flask equipped witha Claisen adapter, thermocouple, stir bar and nitrogen bubbler. AqueousHCl solution (2M, 1.14 L, 2.29 mol) was added and the resulting mixturewas heated at 40° C. for 8 h. Then the mixture was stirred overnight atroom temperature. The mixture was extracted three times with 2 L ofethyl acetate. The combined organic layers were concentrated to give(1-oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde. LC-MS (IE, m/z): 177(M+1)⁺.

Intermediate 2

5-bromo-4-methyl-2-benzofuran-1(3H)-one

Step A: (3-bromo-2-methylphenyl)methanol: To a solution of3-bromo-2-methyl benzoic acid (35 g, 163 mmol) in THF (200 mL) was addedBorane THF Complex (1.0 M, 212 mL, 212 mmol). The mixture was allowed tostir for 24 h. TLC showed one single product spot. The reaction wasquenched with water. The solvent THF was removed under reduced pressure.The resulting solid was dissolved in ethyl acetate (500 mL), washed with1N HCl, sodium carbonate, and brine. The organic layer was dried oversodium sulfate and concentrated to afford(3-bromo-2-methylphenyl)methanol. ¹H NMR (500 MHz, CDCl₃) δ 7.76 (d,J=8.0 Hz, 1H), 7.63 (d, J=8.0 Hz, 1H), 5.30 (s, 2H), 2.42 (s, 3H).

Step B: 5-bromo-4-methyl-2-benzofuran-1(3H)-one: To a flask charged with(3-bromo-2-methylphenyl)methanol (6.0 g, 30 mmol) was added a 1M TFAsolution of thallium trifluoroacetate (16.2 g, 29.8 mmol). The mixturewas stirred at RT overnight. Analysis by TLC showed no starting materialremaining. The solvent was removed under vacuum, and the residue waspumped under high vacuum for 30 min to ensure complete removal of TFA.To the residue was then added palladium(II) chloride (529 mg, 2.98mmol), lithium chloride (2.53 g, 59.7 mmol), magnesium oxide (2.41 g,59.7 mmol), and MeOH (150 mL). The reaction was flushed with CO twice,and kept under CO at room temperature. Analysis by LC showed a bigproduct spot within 2 hours. To this solution was added ethyl acetate toprecipitate the salts. The black solution was filtered through a CELITE®pad, washed with EtOAc, adsorbed onto silica and purified by silica gelchromatography to afford title compound. ¹H-NMR (500 MHz, CDCl₃) δ ppm7.71 (d, J=8.0 Hz, 1H), 7.58 (d, J=8.0 Hz, 1H), 5.25 (s, 2H), 2.37 (s,3H).

Intermediate 3

(4-Methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde

Step A: 4-Methyl-5-prop-2-en-1-yl-2-benzofuran-1(3H)-one: To a flaskcharged with 5-bromo-4-methyl-2-benzofuran-1(3H)-one (320 mg, 1.409mmol) and a stir bar was added allyl tri-n-butyltin (0.655 mL, 2.11mmol), Pd(PPh₃)₄ (244 mg, 0.211 mmol), lithium chloride (179 mg, 4.23mmol), and toluene (15 mL). The reaction was purged with nitrogen 2times then was heated at reflux for 4 hours. The product was separatedby silica gel chromatography to give4-methyl-5-prop-2-en-1-yl-2-benzofuran-1(3H)-one.

Step B: (4-Methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde: Asolution of the above olefin (220 mg, 1.2 mmol) in MeOH (20 mL) wascooled to −78° C. To this solution was bubbled ozone until the reactionturned blue. Nitrogen was bubbled through the reaction to drive offexcess ozone, followed by addition of DMS (0.870 mL, 11.7 mmol). Thereaction was allowed to warm up to RT. The crude product was purified byflash chromatography to afford the title compound. ¹H-NMR (500 MHz,CDCl₃) δ ppm 9.78 (s, 1H), 7.75 (d, J=7.5 Hz, 1H), 7.34 (d, J=7.5 Hz,1H), 5.27 (s, 2H), 3.90 (s, 2H), 2.23 (s, 3H).

Intermediate 4

4-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 5-ethenyl-4-methyl-2-benzofuran-1(3H)-one:5-Bromo-4-methyl-2-benzofuran-1(3H)-one (598 mg, 4.47 mmol), potassiumvinyl trifluoroborate (507 mg, 2.23 mmol), PdCl₂(dppf)-CH₂Cl₂Adduct (182mg, 0.223 mmol), and TEA (0.622 mL, 4.47 mmol) were added to 10 mLethanol in a 20 mL microwave tube. The tube was sealed and degassed,then heated to 140° C. for 20 min. Analysis by LC-MS showed productpeak. The reaction mixture was diluted with ethyl acetate, washed withbrine twice, dried and evaporated to dryness. The crude product waspurified by MPLC chromatography using a 120 g Redi-sep column and 0-80%EtOAc/Hexane solvent system to yield5-ethenyl-4-methyl-2-benzofuran-1(3H)-one. ¹H-NMR (500 MHz, CDCl₃): δppm 7.76 (d, J=8 Hz, 1H), 7.03(dd, J=11, 17 Hz, 1H), 5.84 (d, J=17 Hz,1H), 5.55 (d, J=11 Hz, 1H), 5.29 (s, 2H), 2.34 (s, 3H); LC-MS: M+1=175;

Step B: 4-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one:5-ethenyl-4-methyl-2-benzofuran-1(3H)-one (1.46 g, 8.38 mmol) was addedto DCM (25 mL) at 0° C. then mCPBA (2.89 g, 16.8 mmol) was added and themixture was stirred at RT overnight. The reaction mixture was washedonce each with saturated aqueous Na₂S₂O₃, NaHCO₃, and brine. The organiclayer was dried over Na₂SO₄, filtered, and evaporated to dryness. Thecrude material was purified by MPLC chromatography through 120 gRedi-sep column eluting with 0-80% EtOAc/hexane solvent system to yieldtarget 4-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one. ¹H-NMR (500 MHz,CDCl₃): δ ppm 7.77 (d, J=8 Hz, 1H), 7.43 (d, J=8 Hz, 1H), 5.30 (s, 2 H),4.12 (s, 1 H), 3.27 (t, J=4 Hz, 1 H), 2.735 (dd, J=2.2, 5.5 Hz, 1H),2.43 (s, 3H). LC-MS: M+1=191.

Intermediates 4A and 4B (Method 1)

4A: 4-methyl-5-[(2S)-oxiran-2-yl]-2-benzofuran-1(3H)-one 4B:4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one

Racemic 4-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one was resolved on aChiralPak® AD-H column (5×25 cm) under supercritical fluidchromatography (SFC) conditions on a Berger MGIII preparative SFCinstrument. The racemate was diluted to 50 mg/mL in 1:1 DCM:MeOH. Theseparation was accomplished using 10% EtOH/CO₂, flow rate 200 mL/min,100 bar, 25° C. 500 ul Injections were spaced every 2.12 mins. The fastepoxide (4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one, 4B)eluted first, and the slow epoxide(4-methyl-5-[(2S)-oxiran-2-yl]-2-benzofuran-1(3H)-one, 4A) elutedsecond.

Alternatively, the resolution could also be achieved using a mobilephase of 8% MeOH 98% CO₂ with a flow rate of 100 mL/min. In that casethe sample was prepared by dissolving in methanol, 20 mg/mL, and using a1 mL volume per injection. After separation, the fractions were driedoff via rotary evaporator at bath temperature 40° C.

The absolute stereochemistry of each enantiomer was inferred based onthe X-ray crystal structure determination of a final compound made with4B and by Mosher ester and Trost ester HNMR analysis of esters madestarting from 4B. Both epoxide isomers find utility in the presentinvention.

Intermediate 4B (Method 2)

4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one

Step A: 3-hydroxymethyl-2-methyl phenol: To a 5 L 3 neck RB equippedwith overhead stirrer was charged NaBH₄ (87.0 g, 2.30 mol) and THF (3.0L) and the resulting slurry was cooled to 10° C. To the slurry was thenadded 3-hydroxy-2-methyl benzoic acid (175 g, 1.15 mol) portionwise over20 min (Tmax 17° C.). A stirrable slurry formed, and was aged for anadditional 45 min at 10-15° C. after which BF₃—OEt₂ (321 mL, 2.53 mol)was added slowly over 1.5 hours. The slurry was aged at 10° C.-15° C.for 2 h then assayed for reaction completion (98.5% conversion). Theslurry was cooled to <10° C. and quenched with 931 mL MeOH slowly over1.5 h (gas evolution). The resulting slurry was aged overnight at RT.The batch was cooled to <10° C. then quenched with 1 N HCl (1.5 L) toget a homogeneous solution (pH solution ˜1), which was aged for 30 minand then the organic solvents were removed by rotary evaporation toapproximately 1.8 L of total reaction volume (bath temperature was setto 50° C.; internal temp of concentrate after rotary evaporation was˜40° C.). The slurry was held at 45° C. for 30 min then cooled slowly to15° C. The solids were filtered and washed with cold (15° C.) water(2×300 mL), providing 3-hydroxymethyl-2-methyl phenol. ¹H-NMR (400 MHz,DMSO-d₆): δ 9.11 (s, 1H), 6.95 (t, J=7.8 Hz, 1H), 6.82 (d, J=7.4 Hz,1H), 6.71 (d, J=7.8 Hz, 1H), 4.93 (t, J=5.5 Hz, 1H), 4.44 (d, J=5.5 Hz,2H), 2.06 (s, 3H).

Step B: 4-Bromo-3-hydroxymethyl-2-methyl phenol:3-Hydroxymethyl-2-methyl phenol (113.9 g, 824.0 mmol) was dissolved in amixture of acetonitrile (850 mL) and trifluoroacetic acid (750.0 mL,9.735 mmol) in a 3-neck 5-L flask under nitrogen. The reaction mixturewas cooled to −3° C. N-bromosuccinimide (141 g, 791 mmol) was added over15 minutes, with the temperature during addition in the range of −35 to−33° C. The reaction mixture was allowed to stir for an additional 15min during which time the temperature decreased to −40° C. The coolingbath was removed, and potassium carbonate (741.0 g, 5.358 mmol) dilutedwith water to a total of 1.0 L was added. Off-gassing was observed, andthe temperature increased to 25° C. MTBE (1.5 L) was added, and thereaction mixture was transferred to a separatory funnel. The layers wereseparated. The aqueous layer was diluted with water (500 mL) andextracted with MTBE (1 L)+EtOAc (500 mL), and then MTBE (500 mL)+EtOAc(250 mL). The combined organic layers were washed with water (240 mL)and dried over sodium sulfate. The sodium sulfate was removed byfiltration, washed with additional MTBE and concentrated under reducedpressure. MTBE (684 mL, 2 volumes) was added, and the suspension washeated to 40° C. to produce a homogeneous solution. The solution wasallowed to cool to room temperature. Six volumes of heptane were added,and the suspension was stirred overnight. The suspension was filtered,and the crystals were washed with 4:1 heptane: MTBE (500 mL), followedby heptane (500 mL). The solid was dried under vacuum, providing4-bromo-3-hydroxymethyl-2-methyl phenol. ¹H NMR (400 MHz, DMSO-d₆): δ9.52 (s, 1H), 7.21 (d, J=8.6 Hz, 1H), 6.71 (d, J=8.6 Hz, 1H), 4.88 (t,J=5.1 Hz, 1H), 4.59 (d, J=5.1 Hz, 2H), 2.23 (s, 3H)

Step C: 5-Hydroxy-4-methyl-3H-isobenzofuran-1-one: To a 2 L 3 neck flaskequipped with overhead stirrer, N₂ inlet, and condenser were charged4-bromo-3-hydroxymethyl-2-methyl phenol (100 g, 461 mmol), CuCN (83.0 g,921 mmol), and DMF (500 mL). The solution was sparged with N₂ for 15 minthen heated to 145° C. to obtain a homogeneous solution. The solutionwas aged at 145° C. for 2 h, then the reaction mixture was cooled to 95°C. 41.5 mL water was added (sparged with N₂), and the reaction aged for20 h. The reaction was cooled to RT then the solids filtered throughSOLKA FLOC® and the cake washed with 50 mL DMF. To a 3 L flaskcontaining 1 L EtOAc was added the DMF filtrate. A precipitate coatingformed in bottom of flask. The DMF/EtOAc suspension was filtered throughSOLKA FLOC® and the cake was washed with 250 mL EtOAc. The resultingfiltrate was washed with 5% brine solution (3×500 mL). The aqueouslayers were extracted with 500 mL EtOAc and the combined organics weredried over MgSO₄, filtered and evaporated. The solids were slurried in250 mL MTBE at RT then filtered and washed with 100 mL MTBE. The solidswere dried under vacuum at RT, providing5-hydroxy-4-methyl-3H-isobenzofuran-1-one. ¹H NMR (400 MHz, DMSO-d₆): δ10.52 (s, 1H), 7.51 (d, J=8.3 Hz, 1H), 6.99 (d, J=8.3 Hz, 1H), 5.28 (s,2H), 2.07 (s, 3H).

Step D: 4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yltrifluoromethanesulfonate 5-Hydroxy-4-methyl-3H-isobenzofuran-1-one(46.8 g, 285 mmol) was suspended in dichloromethane (935 mL) in 2-Lround bottom flask equipped with overhead stirrer under nitrogen.Triethylamine (59.5 mL, 427 mmol) was added, and the reaction mixturewas cooled in an ice bath to 3.8° C. Trifluoromethanesulfonic anhydride(67.4 mL, 399 mmol) was added via addition funnel over 50 min, keepingthe temperature <10° C. After stirring the reaction mixture for anadditional 15 min, the reaction mixture was quenched with water (200mL), then stirred with DARCO® KB (activated carbon, 25 g) for 15 min.The biphasic mixture was filtered over SOLKA FLOC®, washing withadditional dichloromethane, and transferred to a reparatory funnel,whereupon it was diluted with additional water (300 mL). The layers wereseparated, and the organic layer was washed with water (500 mL) and 10%brine (200 mL). The dichloromethane solution was dried over sodiumsulfate, filtered and evaporated. The solid was adsorbed onto silica gel(27.5 g) and eluted through a pad of silica gel (271 g) with 25% ethylacetatehexanes. The resulting solution was concentrated under vacuumwith the product crystallizing during concentration. The suspension wasfiltered, the solid washed with heptane and dried under vacuum andnitrogen, providing trifluoromethanesulfonic acid4-methyl-1-oxo-1,3-dihydro-isobenzofuran-5-yl ester. ¹H NMR (400 MHz,CDCl₃): δ 7.87 (d, J=8.4 Hz, 1H), 7.47 (d, J=8.4 Hz, 1H), 5.32 (s, 2H),2.41 (s, 3H)

Step E: 5-(1-Butoxy-vinyl)-4-methyl-3H-isobenzofuran-1-one: To a 1 L3-neck was charged trifluoromethanesulfonic acid4-methyl-1-oxo-1,3-dihydro-isobenzofuran-5-yl ester (63.0 g, 213 mmol),DMF (315 mL), butyl vinyl ether (138 mL, 1063 mmol)) then Et₃N (35.6 mL,255 mmol). The solution was sparged with N₂ for 20 min. To the solutionwas added Pd(OAc)₂ (1.19 g., 5.32 mmol) and DPPP (2.41 g., 5.85 mmol)and sparged for an additional 10 min then heated to 80° C. After a 1 hrage, the solution was cooled to <10° C. then quenched with 630 mL EtOAcand washed with 5% NH₄Cl (2×315 mL), 10% brine (2×315 mL), dried overMgSO₄, filtered, concentrated by rotary evaporation and flushed withEtOAc (3×100 mL) to remove excess butyl vinyl ether, providing crude5-(1-butoxy-vinyl)-4-methyl-3H-isobenzofuran-1-one. ¹H NMR (400 MHz,DMSO-d₆): δ 7.67 (d, J=7.7 Hz, 1H), 7.48 (d, J=7.7 Hz, 1H), 5.42 (s,2H), 4.54 (d, J=2.3 Hz, 1H), 4.27 (d, J=2.3 Hz, 1H), 3.85 (t, J=6.4 Hz,2H), 2.27 (s, 3H), 1.71-1.64 (m, 2H), 1.46-1.37 (m, 2H), 0.92 (t, J=7.4Hz, 3H)

Step F: 5-(2-Bromo-acetyl)-4-methyl-3H-isobenzofuran-1-one: To a 1 L3-neck flask equipped with overhead stirrer was added crude5-(1-butoxy-vinyl)-4-methyl-3H-isobenzofuran-1-one (55.8 g) and THF (315mL). The solution was cooled to <5° C. after which water (79 mL) wasadded and the solution was maintained at <5° C. NBS (41.6 g) was thenadded portion-wise while maintaining Tmax=19° C. The solution was thenwarmed to RT for 30 minutes. HBr (48%, 0.241 mL) was added and thereaction was aged at RT for approximately 1 h after which 236 mL waterwas then added to the batch. A water bath is used to maintain temp at20° C. Another 315 ml, of water was added (solvent composition 1:2THF:water) and the slurry was cooled to 15° C. The resulting solids werefiltered and washed with cold 1:2 THF:water (15° C.): 150 mLdisplacement wash followed by 100 mL slurry wash. The solids were driedunder vacuum at RT to provide5-(2-bromo-acetyl)-4-methyl-3H-isobenzofuran-1-one. ¹H NMR (400 MHz,DMSO-d₆): δ 7.99 (d, J=7.8 Hz, 1H), 7.82 (d, J=7.8 Hz, 1H), 5.49 (s,2H), 4.92 (s, 2H), 2.33 (s, 3H)

Step G: 4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one5-(2-Bromo-acetyl)-4-methyl-3H-isobenzofuran-1-one (48.8 g., 181 mmol)was charged to a 5 L 3 neck round bottom equipped with overhead stirrer,thermocouple, and heating mantle. 2-Propanol (1.22 L) was added,followed by 610 mL of pH 7 0.1M potassium phosphate buffer. Buffersolution (610 mL) was charged to a 1.0 L erlenmeyer, and 2.44 g of NADPwas added to the erlenmeyer and swirled to dissolve. A reducing enzyme,KRED MIF-20 (2.44 g) (available from Codexis, Inc., 200 Penobscot Drive,Redwood City, Calif. 94063, www.codexis.com, tel. 1-650-421-8100) wasadded to the erlenmeyer flask and the mixture was swirled to dissolvethe solids. The resulting solution was added to the 5 L round bottom,which was then heated to 28° C. and aged for 6 hours, at which point thereaction was cooled to RT and triethylamine (50.2 mL, 360 mmol) wasadded. The resulting solution was aged at 40° C. for 1 h. The lightslurry solution was cooled to RT, after which 122 g NaCl was added. Thesolution was aged at RT then extracted with 1.22 L isopropyl acetate(IPAc). The aqueous layer was re-extracted with 400 mL IPAc and thecombined organics were washed with 400 mL 20% brine solution, dried overMgSO₄, filtered and concentrated by rotary evaporation. The resultingsolids were taken up in 100 ml, IPAc (thick slurry). Hexanes were added(400 mL) and the suspension aged at RT then filtered and washed w 5:1Hexanes:IPAc solution (150 mL). The crystalline solids were dried undervacuum at RT to provide4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one. ¹H NMR (400 MHz,CDCl₃): δ 7.75 (d, J=8.1 Hz, 1H), 7.42 (d, J=8.1 Hz, 1H), 5.28 (s, 2H),4.10 (dd, J=4.0, 2.8, 1H), 3.26 (dd, J=5.6, 4.0, 1H), 2.72 (dd, J=5.6,2.8, 1H), 2.42 (s, 3H).

Intermediate 5

(R)-2-Methoxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)acetaldehyde

Step A:(R)-5-(2-Hydroxy-1-methoxyethyl)-4-methylisobenzofuran-1(3H)-one: To asolution of (S)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (2.00 g,10.5 mmol) in MeOH (20 mL) was added p-toluenesulfonic acid monohydrate(0.100 g, 0.526 mmol). After heating at 80° C. for 48 h, the reactionmixture was cooled to RT and then concentrated. The crude product waspurified by column chromatography eluting with 0-45% EtOAc/Hexane. LC-MS(IE, m/z): 223.2 (M+1)⁺.

Step B:(R)-2-Methoxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)acetaldehyde:(R)-5-(2-Hydroxy-1-methoxyethyl)-4-methylisobenzofuran-1(3H)-one (500mg, 2.25 mmol) was dissolved in DCM (10 mL) and treated with Dess-Martinperiodinane (954 mg, 2.25 mmol). The reaction mixture was stirred atroom temperature under nitrogen overnight. The crude product was useddirectly. LC-MS (IE, m/z): 239.2 (M+H₂O+1)⁺.

Intermediate 6

5-(1,2-Dihydroxypropyl)-4-methylisobenzofuran-1(3H)-one

Step A: (E)-4-Methyl-5-(prop-1-en-1-yl)isobenzofuran-1(3H)-one: ToPd(dppf)Cl₂ (0.220 g, 0.338 mmol), K₃PO₄ (6.75 mL, 1 M in water, 6.75mmol) in THF (22 mL) was added potassium(E)-trifluoro(prop-1-en-1-yl)borate (0.749 g, 5.06 mmol) and4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yltrifluoromethanesulfonate(I-4B, Method 2, step D, 1.0 g, 3.38 mmol). The reaction mixture wasde-gassed for 10 min and the resulting mixture was stirred overnight at70° C. The reaction mixture was cooled to room temperature and dilutedwith EtOAc and water. After separation of layers, the aqueous layer wasextracted with EtOAc, and combined organic layers were washed withbrine, dried over anhydrous MgSO₄, filtered, concentrated and purifiedby silica gel column chromatography using (0-50%) acetone-hexanes asmobile phase to give the title compound. LCMS: [(M+1)]⁺=189

Step B: 5-(1,2-Dihydroxypropyl)-4-methylisobenzofuran-1(3H)-one: To(E)-4-methyl-5-(prop-1-en-1-yl)isobenzofuran-1(3H)-one (300 mg, 1.59mmol) in acetonitrile/water (10/1, 18 mL) was added NMO (243 mg, 2.07mmol) and potassium osmate(VI) dihydrate (29.4 mg, 0.080 mmol) at 0° C.The reaction mixture was allowed to warm to rt and stirred at rt for 2h. TLC showed the reaction completed. The reaction mixture was filteredthrough a pad of silica gel, rinsed with 10% MeOH/DCM. The crude productwas purified with column chromatography (0-10% MeOH/DCM) to give thetitle compound. LCMS: [(M+1)]⁺=223

Intermediate 7

6-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 5-prop-2-en-1-yl-2-benzofuran-1(3H)-one: A mixture of5-bromo-2-benzofuran-1(3H)-one (15.0 g, 70.4 mmol),allyl-tributyl-stannane (25.6 g, 77.5 mmol), LiCl (11.8 g, 282 mmol) andPd(PPh₃)₄ (1.2 g, 1.0 mmol) in 100 mL toluene was heated under N₂ at90˜100° C. overnight. After cooling to r.t., the mixture was dilutedwith 250 mL EtOAc and filtered. The filtrate was washed with water andbrine, dried over anhydrous Na₂SO₄ and concentrated to dryness. Theresidue was purified via column (DCM/Petrol Ether=1:5) to give the titlecompound.

Step B: 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one: To a solution of5-prop-2-en-1-yl-2-benzofuran-1(3H)-one (13.5 g, 45.2 mmol) in 200 mLDCM/MeOH (V/V=1:1) was bubbled O₃ at −78° C. for 30 min, and N₂ wasbubbled for another 15 min at −78° C. Then 20 mL of Me₂S were added, andthe mixture was stirred at r.t. overnight before concentrating todryness. The residue was dissolved in MeOH (100 mL) and then cooled to0° C. NaBH₄ (5.90 g, 155 mmol) was added in portions. The resultingmixture was stirred at 0° C. for 1 h, then quenched with citric acid(aq.) and extracted three times with EtOAc. The combined organic layerswere washed with NaHCO₃ (aq.) and brine, dried over anhydrous Na₂SO₄ andconcentrated to dryness. The residue was purified via columnchromatography (EtOAc/Petrol Ether=1:5) to give the title compound.¹H-NMR (400 MHz, CDCl₃) δ ppm 7.86 (d, J=7.8 Hz, 1H), 7.41 (d, J=7.8 Hz,1H), 7.38 (s, 1H), 5.29 (s, 2H), 3.92-3.98 (m, 2H), 3.01 (t, J=6.4 Hz,2H).

Step C: 5-(2-hydroxyethyl)-6-iodo-2-benzofuran-1(3H)-one: To a cooled(0° C.) solution of 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (9.00 g,50.6 mmol) in 100 mL of TfOH was added NIS (12.5 g, 55.6 mmol), then themixture was stirred at 0° C. for 2 hrs and then poured into ice-water(500 mL). The solution was extracted three times with 500 mL of EtOAcand the combined organic layers were washed with saturated NaHCO₃ andbrine, dried over anhydrous sodium sulfate, filtered and concentrated.The residue was purified by column chromatography (EtOAc PetrolEther=1:5) to give the desired5-(2-hydroxyethyl)-6-iodo-2-benzofuran-1(3H)-one and regioisomerby-product 5-(2-hydroxyethyl)-4-iodo-2-benzofuran-1(3H)-one. ¹H-NMR (400MHz, CDCl₃) δ ppm 7.84 (d, J=7.8 Hz, 1H), 7.46 (d, J=7.8 Hz, 1H), 5.09(s, 2H), 3.93 (q, J=6.3 Hz, 2H), 3.16 (t, J=6.3 Hz, 2H), 1.45 (t, J=5.5Hz, 1H).

Step D: 5-(2-hydroxyethyl)-6-methyl-2-benzofuran-1(3H)-one: To a flaskcharged with 5-(2-hydroxyethyl)-6-iodo-2-benzofuran-1(3H)-one (6.00 g,19.7 mmol) and a stir bar was added Pd₂(dba)₃ (452 mg, 0.493 mmol), PPh₃(1 g, 4 mmol) and NMP (50 mL). The mixture was purged with N₂ and heatedto 50° C. for 10 min, followed by addition of CuI (375 mg, 1.97 mmol).After the mixture was heated for another 10 min, Sn(CH₃)₄ (5.30 g, 29.6mmol) was added into the reaction, and it was heated to 120° C. for 2 h.After cooling to room temperature, the mixture was diluted withsaturated NH₄Cl (200 mL) and extracted with EtOAc (3 times 200 mL). Thecombined organic layers were washed with water and brine, dried overanhydrous sodium sulfate, filtered and concentrated. The residue waspurified by prep-HPLC to give the title compound. ¹H-NMR (400 MHz,CDCl₃) δ ppm 7.72 (s, 1H), 7.33 (s, 1H), 5.27 (s, 2H), 3.93 (t, J=6.3Hz, 2H), 3.01 (t, J=6.3 Hz, 2H), 2.44 (s, 3H).

Step E: 2-(6-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethylmethanesulfonate: To a solution of5-(2-hydroxyethyl)-6-methyl-2-benzofuran-1(3H)-one (1.20 g, 6.25 mmol)and TEA (2.5 g, 25 mmol) in DCM (100 mL) was added MsCl (1.40 g, 12.5mmol) at 0° C. The mixture was stirred at ambient temperature overnight,then was washed with water and brine. The organic layer was dried andconcentrated to dryness. The collected title compound was used for thenext step without any purification.

Step F: 5-ethenyl-6-methyl-2-benzofuran-1(3H)-one: To a mixture of2-(6-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl methanesulfonate(2.00 g, 7.41 mmol) and TEA (5 mL) in DCM (50 mL) was added DBU (5 mL)slowly at 0° C. The mixture was stirred at r.t. overnight, and then wasdiluted with 50 mL of DCM, washed with 2 N HCl in three times and brine.The organic layer was dried and concentrated to dryness. The residue waspurified by prep-TLC to give 5-ethenyl-6-methyl-2-benzofuran-1(3H)-one.

Step G: 6-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one: To a solution of5-ethenyl-6-methyl-2-benzofuran-1(3H)-one (1.00 g, 5.75 mmol) in 50 mLof DCM was slowly added mCPBA (3.50 g, 17.4 mmol) in 50 mL of DCM at 0°C. The mixture was warmed to room temperature, and stirred for 2 days.The mixture was washed with aqueous Na₂SO₃ until KI indicator paperdidn't change color. The organic layer was washed with brine and thenconcentrated. The residue was purified via silica column to give thetitle compound. LC-MS M+1 (calc. 191. found 191).

Intermediates 7A and 7B

(R)-6-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one and(S)-6-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one: The title compoundswere obtained by chiral SFC separation of the racemic6-methyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one (I-7) using a chiralpak ADcolumn (250 mm×50 mm, 10 um); mobile phase: A: Supercritical CO₂, B:MeOH, A:B=85:15 at 250 ml/min. First peak to elute (Isomer 7A): ¹HNMR400 MHz CDCl₃, δ 7.68 (s, 1H), 7.36 (s, 1H), 5.24 (d, J=3.6 Hz, 2H),4.05 (dd, J=2.8 Hz, 3.6 Hz, 1H), 3.24 (dd, J=4.0 Hz, 6.4 Hz, 1H), 2.63(dd, J=2.8 Hz, 6.4 Hz, 1H), 2.50 (s, 3H); second peak to elute (Isomer7B): 400 MHz CDCl₃, δ 7.68 (s, 1H), 7.35 (s, 1H), 5.24 (d, J=3.6 Hz,2H), 4.05 (dd, J=2.8 Hz, 3.6 Hz, 1H), 3.24 (dd, J=4.0 Hz, 6.4 Hz, 1H),2.63 (dd, J=2.8 Hz, 6.4 Hz, 1H), 2.50 (s, 3H).

Intermediate 8

(3-oxo-3,6,8,9-tetrahydro-1H-furo[3,4-f]isochromen-6-yl)methyl-4-methylbenzenesulfonate

Step A: 5-bromo-4-iodo-2-benzofuran-1(3H]-one: To a solution of5-bromo-2-benzofuran-1(3H)-one (5.00 g, 23.5 mmol) at 0° C. in TfOH (100mL) was added NIS (5.55 g, 24.6 mmol). The mixture was stirred at roomtemperature over night; LC analysis of the reaction mixture indicatedcompletion of the reaction. The reaction mixture was then poured slowlyinto ice-water (1 L) with stirring. To the solution was then added EtOAc(500 mL) and subsequently stirred for 10 min. The mixture was filteredand the organic layer separated. The aqueous layer was extracted withEtOAc (2×200 mL). The combined organic layers were washed with water(500 mL), brine (500 mL), dried over Na₂SO₄, filtered, and concentratedto dryness; the resulting material was absorbed onto silica gel andseparated with the solvent system of (hexanes/EtOAc=1/1) to yield5-bromo-4-iodo-2-benzofuran-1(3H]-one.

Step B: 5-bromo-4-prop-2-en-1-yl-2-benzofuran-1(3H)-one: A mixture of5-bromo-4-iodo-2-benzofuran-1(3H]-one (2.42 g, 7.13 mmol),allyltributyltin (2.36 g, 7.13 mmol), LiCl (1.50 g, 35.7 mmol) and Pd(PPh₃)₄ (200 g, 0.173 mmol) in toluene (50 mL) was heated at 90-100° C.under N₂ overnight; LC indicated that reaction had gone to completion,to the solution was poured EtOAc (100 mL) and washed with brine. Theorganic layer was dried over Na₂SO₄, filtered and concentrated todryness, absorbed into silica gel and was then separated over silica gelcolumn to give the title compound.

Step C: 5-bromo-4-(2-hydroxyethyl)-2-benzofuran-1(3H)-one: To a solutionof 5-bromo-4-prop-2-en-1-yl-2-benzofuran-1(3H)-one (1.27 g, 5.02 mmol)in MeOH (50 mL) and DCM (50 mL) was bubbled O₃ at −78° C. until thesolution turned blue; excess ozone was removed on high vacuum. After thesolution's color changed to colorless, NaBH₄ (0.8 g, 20 mmol) was addedto the reaction mixture and it was subsequently stirred at roomtemperature for 30 min. LC and TLC indicated that reaction had gone tocompletion. The solvent was removed on high vacuum; the residue was thenre-dissolved in EtOAc and washed with water, dried over Na₂SO₄, filteredand concentrated to dryness. The organic residue was absorbed ontosilica gel and was separated on silica gel column to give the titlecompound.

Step D: 5-ethenyl-4-(2-hydroxyethyl)-2-benzofuran-1(3H)-one: A mixtureof 5-bromo-4-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (0.460 g, 1.78mmol), tributyl(vinyl)tin (0.676 g, 2.13 mmol), LiCl (0.224 g, 5.33mmol) and Pd (PPh₃)₄ (0.10 g, 0.087 mmol) in toluene (50 mL) was heatedat 100-110° C. under N₂ overnight after which TLC indicated that thereaction had gone to completion. Next, EtOAc (100 mL) was poured intothe solution and it was washed with brine, then water, then dried overNa₂SO₄, filtered and concentrated to dryness. The residue was thenabsorbed onto silica gel and separated over silica column to give thetitle compound.

Step E: 4-(2-hydroxyethyl)-5-oxiran-2-yl-2-benzofuran-1(3H)-one:5-Ethenyl-4-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (1.2 g, 5.9 mmol)was added to a flask containing a stir bar. To the flask was then addeddichloromethane (20 mL). The flask was placed in a cool bath of 0° C.;to the flask was poured mCPBA (1.5 g, 8.8 mmol) and the resultingmixture was stirred at room temperature for overnight; LC as well as TLC(hexanes/EtOAc=1/1) indicated that reaction had gone to completion. Thesolution was treated with dichloromethane and washed with NaHCO₃,Na₂S₂O₃, and water, the organic layer was then dried over Na₂SO₄,filtered and concentrated to dryness, it was then treated with AcOH (20mL) and stirred overnight; LC indicated formation of cyclized product.The solvent was removed and the resulting residue was absorbed ontosilica gel and the title compound was isolated with the solvent systemof hexanes/EtOAc (1/1).

Step F:(3-oxo-3,6,8,9-tetrahydro-1H-furo[3,4-f]isochromen-6-yl)methyl-4-methylbenzenesulfonate:6-(Hydroxymethyl)-8,9-dihydro-1H-furo[3,4-f]isochromen-3(6H)-one, in DCM(10 mL) was treated with p-Toluenesulfonyl chloride (0.40 g, 2.3 mmol);to the mixture was added pyridine (2 mL) and the resulting mixturestirred at room temperature for 12 h. TLC (hexanes/EtOAc=10.5) and LCindicated the consumption of starting material and formation of thedesired product. Dichloromethane was added to the reaction mixture andit was washed with NaCl, water and dried over Na₂SO₄, filtered andconcentrated to dryness, absorbed onto silica gel and was then subjectedto purification over silica gel; the title compound was isolated withthe solvent system of hexanes/EtOAc (10.5). ¹H-NMR (400 MHz, CDCl₃) δppm 7.781 (d, J=8 Hz, 1H), 7.727 (d, J=8 Hz, 1H), 7.367 (d, J=8 Hz, 1H),7.257 (d, J=8.5 Hz, 1H), 7.206 (d, J=8 Hz, 1H), 5.253 (s, 2H), 5.110 (s,1H), 4.481-4.452 (m, 2H), 4.419-4.385 (m, 2H), 4.196-4.153 (m, 2H),2.495 (s, 3H).

Intermediate 9

4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate

Step A: ethyl 4-bromo-2-methyl-3-oxobutanoate: To a solution of ethyl2-methyl-3-oxobutanoate (5.05 g, 35.0 mmol) in water (10 mL) at 0° C.was added bromine (1.81 mL, 35.0 mmol) dropwise over 2 h. The resultingsolution was stirred at rt for 16 h. The reaction mixture was extractedwith ethyl acetate, the organic phase was dried over sodium sulfate andconcentrated to give ethyl 4-bromo-2-methyl-3-oxobutanoate. ¹HNMR (500MHz, CDCl₃), δ4.322-4.274 (m, 2H), 2.455 (s, 2H), 1.991 (s, 3H),1.337-1.309 (t, 3H).

Step B: 4-hydroxy-3-methylfuran-2(5H)-one: Ethyl4-bromo-2-methyl-3-oxobutanoate (7.81 g, 35 mmol) was treated withhydrogen bromide (0.040 mL, 48%, 0.35 mmol) and the mixture was heatedat 100° C. for 6 h. The precipitate was collected by filtration followedby washing with ethyl acetate to give 4-hydroxy-3-methylfuran-2(5H)-one.¹HNMR (500 MHz, CDCl₃), δ4.595 (s, 2H), 3.314 (s, 1H), 1.668 (s, 3H).

Step C: 4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate:To a solution of 4-hydroxy-3-methylfuran-2(5H)-one (400 mg, 3.51 mmol)in dichloromethane (10 mL) at −78° C. was added 2,6-lutidine (0.612 mL,5.26 mmol) and triflic anhydride (0.711 mL, 4.21 mmol) dropwise. Thereaction temperature was maintained at −78° C. for 0.5 h before beingwarmed to rt for 1 h. The mixture was diluted with DCM (100 mL) andwashed with 1N hydrogen chloride (3 times 100 mL), then with dilutedsodium bicarbonate solution, then dried over sodium sulfate, andconcentrated to give the title compound. LCMS: (M+1)⁺: 247.0.

Intermediate 10

tert-Butyl 3,8-diazaspiro[5,5]undecane-3-carboxylate

Step A: tert-Butyl 4-(hydroxymethyl)piperidinecarboxylate: A mixture of70 g of LiAlH₄ in 1500 mL of THF was cooled to 0° C., then 180 g of1-tert-butyl 4-methyl piperidine-1,4-dicarboxylate in THF was addeddropwise. When the reaction was finished, 200 mL of ethyl acetate andsolid anhydrous Na₂SO₄. Water was added until the solution became clear.The mixture was filtered and the filtrate was evaporated to afford thetitle compound.

Step B: tert-Butyl 4-formypiperidinecarboxylate: The solution of 200 mLof DMSO in CH₂Cl₂ cooled to −78° C., 118 mL of (COCl)₂ was addeddrop-wise. Then 255 g of tert-butyl4-(hydroxymethyl)piperidinecarboxylate was also added drop-wise. Themixture was stirred for 4 h. After the reaction was finished, 638 mL ofEt₃N was added at −78° C. The organic layer was washed by brine, driedand purified by column chromatography to afford the title compound.

Step C: tert-Butyl 4-formyl-4-propylpiperidinecarboxylate: tert-Butyl4-formypiperidinecarboxylate was dissolved in 66 mL of acrylonitrile,and 5 g of 50% aq. sodium hydroxide solution was added, then the mixturewas heated to 50° C., until the reaction was complete as judged by TLC.The mixture was then poured into 700 mL of ether, then washed with brineand purified with column chromatography to afford title compound.

Step D: tert-Butyl 3,8-diazaspiro[5,5]undecane-3-carboxylate: Tert-butyl4-formyl-4-propylpiperidinecarboxylate (30 g) was dissolved in asaturated solution of ammonia in methanol, and 15 g of Raney Ni wasadded. The reaction mixture was heated to 110° C. at 80 atmospherespressure in a 2 L high-pressure autoclave. The mixture was filtered toremove the catalyst and the filtrate was concentrated to give residuewhich was purified by column chromatography to afford tert-butyl3,8-diazaspiro[5,5]undecane-3-carboxylate.

Intermediate 11

tert-Butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: The titlecompound is commercially available from a number of vendors, forexample, Shanghai AQ BioPharma Co., Ltd, catalog #ABP1882.Alternatively, it may be prepared in various ways, including theprocedure described below.

Step A: 1-tert-Butyl 4-methyl4-(cyanomethyl)piperidine-1,4-dicarboxylate: To a solution ofcommercially available 1-tert-butyl 4-methylpiperidine-1,4-dicarboxylate (200 g, 0.82 mol) in anhydrous THF (2 L)was added LDA (2M in THF, 575 mL, 1.15 mol) drop-wise at −65° C. underN₂. The mixture was stirred at −65° C. for 1.5 h. To the mixture wasadded bromoacetonitrile (148 g, 1.23 mol) in anhydrous THF (500 mL) at−65° C. The mixture was stirred at −65° C. for 1 h, then warmed up toroom temperature and stirred overnight. The reaction was quenched withwater (800 mL) at 0° C. and the combined reaction mixture wasconcentrated in vacuum to give a crude product, which was extracted withethyl acetate (1 L three times). The combined organic phases were washedwith brine (1 L) and dried over Na₂SO₄. The organic layer was filteredand the filtrate was concentrated under vacuum to give a crude product,which was purified by column chromatography on silica gel eluting withpetroleum ether/ethyl acetate (from petroleum ether to 2/1) to give thetitle compound. ¹H-NMR (400 MHz, CDCl₃) δ 3.900-3.750 (m, 5H),3.120-3.000 (m, 2H), 2.612-2.562 (m, 2H), 2.190-2.111 (m, 2H),1.590-1.502 (m, 2H), 1.402 (s, 9H).

Step B: tert-Butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: Asuspension of 1-tert-butyl 4-methyl4-(cyanomethyl)piperidine-1,4-dicarboxylate (70.0 g, 247.9 mmol) andRaney Ni (60 g) in MeOH (1500 mL) and NH₃.H₂O (80 mL) was stirred at 2MPa of hydrogen pressure at 50° C. for 18 h. The reaction mixture wasfiltered through a pad of CELITE® and the filtrate was concentratedunder vacuum to give a crude product, which was washed with ethylacetate (200 mL) to give the title compound. ¹H-NMR (400 MHz, CDCl₃) δ6.05 (s, 1H), 4.0 (s, 2H), 3.37-3.34 (m, 2H), 3.02-2.96 (m, 2H),2.08-2.05 (m, 2H), 1.88-1.87 (m, 2H), 1.51-1.41 (m, 11H)

Intermediate 12

3-oxo-2,8-diaza-spiro[4,5]decane-8-carboxylic acid tert-butyl ester

Step A: tert-butyl 4-(2-ethoxy-2-oxoethylidene)piperidine-1-carboxylate:Into a 10-L 4-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen was placed a suspension of NaH (74.0 g,2.16 mol 1.05 equiv, 70%) in tetrahydrofuran (2000 mL) at 0° C., thenethyl 2-(diethoxyphosphoryl)acetate (514 g, 2.06 mol, 1.05 equiv, 98%)was added dropwise with stirring at 0° C. This was followed by theaddition of a solution of tert-butyl 4-oxopiperidine-1-carboxylate (400g, 1.97 mol, 1.00 equiv, 98%) in tetrahydrofuran (1200 mL) dropwise withstirring at 0° C. The resulting solution was stirred for 60 min at roomtemperature, then quenched by the addition of 2000 mL of water. Theresulting solution was extracted with 2×1000 mL of ethyl acetate. Theorganic layers were combined, dried over anhydrous magnesium sulfate andconcentrated under vacuum. The residue was washed with 1×1000 mL ofhexane and dried to afford tert-butyl4-(2-ethoxy-2-oxoethylidene)piperidine-1-carboxylate.

Step B: tert-butyl4-(2-ethoxy-2-oxoethyl)-4-(nitromethyl)piperidine-1-carboxylate: Into a3000-mL 4-necked round-bottom flask was placed potassium carbonate (93.2g, 662 mmol, 0.50 equiv) and DMSO (2000 mL). The resulting solution washeated to 80° C. This was followed by the addition of tert-butyl4-(2-ethoxy-2-oxoethylidene)piperidine-1-carboxylate (368 g, 1.30 mol,1.00 equiv, 95%) and CH₃NO₂ (417 g, 6.70 mol, 5.00 equiv, 98%) slowly.The resulting solution was stirred for 120 min at 90° C. After beingcooled to room temperature, the reaction mixture was adjusted to ph 5with HCl (0.5 mol/L) and diluted with 2000 mL of water. The resultingsolution was extracted with 3×1500 mL of ether. The organic layers werecombined, washed with 1×2000 mL of water and 1×2000 mL of saturatedbrine, dried and concentrated under vacuum. The residue was applied ontoa silica gel column and eluted with ethyl acetate/petroleum ether(1:20˜1:15˜1:10) to afford the title compound.

Step C: 3-oxo-2,8-diaza-spiro[4,5]decane-8-carboxylic acidtert-butylester: A mixture of tert-butyl4-(2-ethoxy-2-oxoethyl)-4-(nitromethyl)piperidine-1-carboxylate (330 g,990 mmol, 1.00 equiv, 99%) and Ni (40 g, 0.15 equiv) in ethanol (1200mL) was stirred for 24 h under a hydrogen atmosphere at roomtemperature. The solid was filtered out. The filtrate was concentratedunder vacuum. The crude product was purified by re-crystallization fromether to afford the title compound. LC-MS (ES, m/z): 199 [M+H]⁺; ¹H-NMR(400 MHz, CDCl₃, ppm): 1.447-1.476(9H, s), 1.597-1.673(4H, m, J=30.4Hz), 2.235(2H, s), 3.226(2H, s), 3.284-3.348(2H, m, J=25.6 Hz),3.507-3.567(2H, m, J=24 Hz), 6.048(1H, s).

Intermediate 13

tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

Step A: 1-tert-Butyl 4-methyl4-(2-methylallyl)piperidine-1,4-dicarboxylate:A solution ofN-Boc-piperidine-4-carboxylic acid methyl ester (2.00 g, 8.22 mmol) inTHF (40 mL) was cooled to −78° C. Under nitrogen, a 2.0 M THF solutionof LDA (6.17 mL, 12.3 mmol) was added dropwise. The reaction mixture wasstirred at −78° C. for 30 minutes before a solution of3-bromo-2-methylpropene (1.60 g, 11.9 mmol) in THF (2 mL) was added.After the reaction was stirred for 1 hour at this temperature, a samplewas taken for LC-MS analysis and it showed that the reaction wascompleted. The reaction was quenched by adding saturated ammoniumchloride solution (5 mL) and the mixture was allowed to warm up to roomtemperature. The mixture was then extracted with EtOAc (50 mL twice).The combined organic layers were washed with brine (30 mL), dried overanhydrous sodium sulfate and filtered. The filtrates were concentratedand the crude product was purified by column chromatography eluting with0-30% ethyl acetatehexane to give the title compound. LC-MS (IE, m/z):242.21 [M−56+1]⁺.

Step B: 1-tert-Butyl 4-methyl4-(2-oxopropyl)piperidine-1,4-dicarboxylate: To a solution of1-tert-butyl 4-methyl 4-(2-methylallyl)piperidine-1,4-dicarboxylate (2.2g, 7.4 mmol) in dioxane/water (60 mL, 1/1) under nitrogen was addedosmium tetroxide (0.038 g, 0.15 mmol) and sodium periodate (2.88 g, 13.5mmol). The mixture was stirred at room temperature for 3 hours. Themixture was then diluted with dichloromethane (50 mL), and washed with20% Na₂S₂O₃ (20 mL). The organic layers were combined and washed withbrine (20 mL), dried over anhydrous sodium sulfate, and filtered. Thefiltrates were concentrated and the residue was purified by columnchromatography eluting with 0-60% ethyl acetatehexane to afford1-tert-butyl 4-methyl 4-(2-oxopropyl)piperidine-1,4-dicarboxylate. LC-MS(IE, m/z): 322.26 (M+23)⁺.

Step C: tert-Butyl3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: 1-tert-Butyl4-methyl 4-(2-oxopropyl)piperidine-1,4-dicarboxylate (1.15 g, 3.84 mmol)in methanol (25 mL) was treated with ammonium acetate (3.85 g, 49.9mmol), sodium cyanoborohydride (0.681 g, 10.83 mmol) and magnesiumsulfate (2.54 g, 21.1 mmol). The mixture was heated at 80° C. in asealed tube for 12 hours. The reaction mixture was filtered through apad of CELITE® and the filter cake was washed with methanol. Thefiltrates were then concentrated and the residue was purified by columnchromatography eluting with 0-10% methanol/ethyl acetate to afford thetitle compound. LC-MS (IE, m/z): 291.27 (M+23)⁺

Intermediates 13A and 13B

(S)-tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate;and (R)-tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate wassubjected to SFC purification. The two enantiomers were resolved on aChiralcel IA column eluting with 30% MeOH:MeCN (2:1)/CO₂ (100 bar, 35°C.). The faster eluting isomer was determined to be (S)-tert-Butyl3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate and the slowereluting isomer was (R)-tert-Butyl3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate based onVibrational Circular Dichroism (VCD) spectroscopy analysis. LC-MS (IE,m/z): 291 (M+23)⁺.

Intermediate 14

4-(2,8-diazaspiro[4.5]decan-2-yl)furan-2(5H)-one: Commercially availablefuran-2,4(3H,5H)-dione (0.433 g, 4.33 mmol) and tert-butyl2,8-diazaspiro[4.5]decane-8-carboxylate (commercially available frommultiple vendors, acetic acid salt, 0.65 g, 2.2 mmol) in 20 mL i-PrOHwas heated in a sealed tube at 110° C. overnight. The solid was filteredoff and the filtrate was concentrated under vacuum. The residue wasdissolved in 30 mL DCM and 5 mL TFA and stirred at rt for 1 h. Themixture was concentrated, and the residue was purified by preparativeTLC (10% 2N NH₃ in methanol-DCM). LCMS: [(M+1)]⁺=223

Intermediate 15

4-(2,9-Diazaspiro[5.5]undecan-2-yl)furan-2(5H)-one

Step A: tert-Butyl2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecane-9-carboxylate

To commercially available 4-bromofuran-2(5H)-one (128 mg, 0.786 mmol) inTHF (4 mL) was added Hunig's Base (275 μL, 1.57 mmol) and tert-butyl3,8-diazaspiro[5,5]undecane-3-carboxylate (200 mg, 0.786 mmol). Thereaction mixture was stirred at 76° C. overnight, concentrated andpurified by column chromatography (0-10% MeOH in DCM) to afford thetitle compound. LCMS: [(M+1)]⁺=337

Step B: 4-(2,9-Diazaspiro[5.5]undecan-2-yl)furan-2(5H)-one: Totert-butyl2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecane-9-carboxylate(266 mg, 0.792 mmol) in DCM (2 mL) was added TFA (2 mL, 26.0 mmol) at 0°C. The reaction mixture was stirred at room temperature for 1 h, thenconcentrated under reduced pressure, then placed on the high vacuum. Theresidue was dissolved in MeOH and loaded onto a 2 g Bond Elut SCX column(pre-rinsed with MeOH). These were rinsed with MeOH, and the product waseluted via 2M NH₃ in MeOH to afford4-(2,9-diazaspiro[5.5]undecan-2-yl)furan-2(5H)-one. LC/MS: [(M+1)]⁺=237

Intermediate 16

2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(1.83 g, 7.20 mmol), commercially available 4-bromofuran-2(5H)-one (1.41g, 8.63 mmol), Xantphos (0.416 g, 0.720 mmol), water (0.389 mL, 21.6mmol), and potassium carbonate (1.989 g, 14.39 mmol) in toluene (50 mL)was degassed with nitrogen followed by addition of palladium acetate(0.081 g, 0.36 mmol). The resulting mixture was heated at 65° C. for 16h. After filtration through CELITE®, the filtrate was concentrated andthe residue was purified on silica gel column using EtOAc /hexane aseluting solvents to give the title compound. LC/MS: (M+1)⁺: 337.18.

Step B: 2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(5.70 g, 16.9 mmol) in methylene chloride (10 mL) was addedtrifluoroacetic acid (26.1 mL, 339 mmol) and the resulting solution wasstirred at rt for 1 h. After concentration the residue was basified onion exchange column followed by washing with 1N ammonia in methanolsolution to give2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one. LC/MS:(M+1)⁺: 237.06.

Intermediate 17

2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:To a mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(I-11, 80.0 g, 315 mmol) and4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (I-9, 85.2g, 346 mmol), Xantphos (13.6 g, 23.6 mmol), Cs₂CO₃ (153.7 g, 471.8 mmol)in toluene (1200 mL), was added Pd₂(dba)₃ (7.20 g, 7.86 mmol) under N₂.The resulting reaction mixture was heated to 90° C. and stirred under N₂for 18 h. The mixture was filtered through a pad of CELITE® and thefiltrate was concentrated. The residue was purified by precipitation togive tert-butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate.¹H NMR (400 MHz, CDCl₃) δ 5.23 (s, 2H), 4.02-3.99 (m, 4H), 3.06-3.05 (m,2H), 2.15-2.11 (m, 2H), 2.02 (s, 3H), 1.87-1.81 (m, 2H), 1.51-1.41 (m,11H)

Step B:2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a mixture of tert-butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(57.0 g, 163 mmol) in EtOAc (180 mL) was added saturated HCl (g)/EtOAc(712 mL) at 0° C. The resulting reaction mixture was stirred at roomtemperature for 3 h. The mixture was filtered and the filtrate wasconcentrated to give the HCl salt. To a mixture of HCl salt (54.2 g, 189mmol) in MeOH (550 mL) was added NaHCO₃ (31.8 g, 378 mmol) at 0° C. Theresulting reaction mixture was stirred at room temperature for 3 h untilthe pH=8. The mixture was filtered and the filtrate was concentrated.The residue was re-dissolved in MeOH and concentrated until aprecipitate appeared. The mixture was filtered and the filtrate wasconcentrated to give2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneas a free amine. 1H NMR (400 MHz, CD3OD) δ 5.24 (s, 2H), 4.10-4.07 (m,2H), 3.22-3.16 (m, 2H), 2.93-2.87 (m, 2H), 2.22-2.19 (m, 2H), 2.0 (s,3H), 1.94-1.87 (m, 2H), 1.67-1.61 (m, 2H)

Intermediate 18

2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one

Step A: tert-Butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecane-9-carboxylate:A microwave vial was charged with commercially available tert-butyl1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate (Shanghai AQ BioPharmaCo., Ltd, catalog #ABP3640, 100 mg, 0.373 mmol), 4-bromofuran-2(5H)-one(72.9 mg, 0.447 mmol), Pd₂(dba)₃ (17.06 mg, 0.019 mmol), Xantphos (32.3mg, 0.056 mmol), and cesium carbonate (182 mg, 0.559 mmol). The vial wassealed, degassed, and filled with toluene (1.5 mL). The reaction mixturewas heated at 90° C. overnight, and was filtered through CELITE®. Thefiltrate was evaporated to give the crude product, which was purified bycolumn chromatograph (0-10% MeOH/DCM) to afford the title compound.LC/MS: [(M+1−56)]⁺=295

Step B:2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one:tert-Butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecane-9-carboxylate(100 mg, 0.285 mmol) in DCM (2 mL) was treated with TFA (660 μL, 8.56mmol) at 0° C. to give TFA salt. Then a 2 g Bond Elut SCX column wasfirst rinsed with MeOH, the sample was loaded onto the column with MeOH,the cartridge was washed with MeOH drop-wise to remove TFA, and finallyrinsed with 2N NH₃MeOH to provide the title compound as a free amine.LC/MS: [(M+1)]⁺=251

Intermediate 19

2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one

Step A: tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate:A microwave vial was charged with commercially available tert-butyl1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate (Shanghai AQ BioPharmaCo., Ltd, catalog #ABP3640, 100 mg, 0.373 mmol),4-methyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate (110 mg,0.447 mmol), Pd₂(dba)₃ (17 mg, 0.019 mmol), Xantphos (32 mg, 0.056mmol), and cesium carbonate (182 mg, 0.559 mmol). The vial was sealed,degassed, and filled with toluene (1.5 mL). The reaction mixture washeated at 90° C. overnight, and was filtered through CELITE®. Thefiltrate was evaporated to give the crude product, which was purified bycolumn chromatography (0-10% MeOH/DCM) to afford the title compound.LC/MS: [(M+1−56)]⁺=309

Step B:2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one:tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate(130 mg, 0.357 mmol) in DCM (2 mL) was treated with TFA (824 μL, 10.7mmol) at 0° C. to give the TFA salt. Then a 2 g Bond Elut SCX (ionexchange cartridge) was first rinsed with MeOH, the sample was loadedonto the column with MeOH, the cartridge was washed with MeOH dropwiseto remove TFA, and finally rinsed with 2N NH₃/MeOH to provide the titlecompound as a free amine. LC/MS: [(M+1)]⁺=265

Intermediate 20

2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-3-one: Thetitle compound was prepared from3-oxo-2,8-diaza-spiro[4,5]decane-8-carboxylic acid tert-butyl ester and4-bromofuran-2(5H)-one in two steps in an analogous fashion to thatdescribed for2-(5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one (I-18)above. LC/MS: [(M+1)]⁺=237

Intermediate 21

2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-3-one: Thetitle compound was prepared from3-oxo-2,8-diaza-spiro[4,5]decane-8-carboxylic acid tert-butyl ester and4-methyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate in twosteps in an analogous fashion to that described for2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one(I-19) above.

Intermediate 22

3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-Butyl3-methyl-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (I-13) (505 mg,1.88 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (109 mg,0.188 mmol), palladium(II) acetate (21 mg, 0.094 mmol), potassiumcarbonate (520 mg, 3.76 mmol), water (102 μl, 5.65 mmol) andcommercially available 4-bromofuran-2-one (368 mg, 2.26 mmol) in toluene(13 mL) was degassed and then heated at 60° C. for 16 hours. The mixturewas filtered through a pad of CELITE®, and the filter cake was washedwith ethyl acetate. The filtrates were concentrated and the residue waspurified by column chromatography eluting with 10-100% ethylacetatehexane gradient to give the title compound. LC-MS (IE, m/z):373.3 (M+23)⁺.

Step B:3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:tert-Butyl3-methyl-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(90 mg, 0.257 mmol) was dissolved in dichloromethane (2 mL) and treatedwith TFA (1 mL). After stirring at room temperature for 1.5 hours, thereaction mixture was concentrated to remove excess of the reagent andco-evaporated with dichloromethane three times to give the titlecompound. LC-MS (IE, m/z): 251 (M+1)⁺.

Intermediate 22A

(S)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared in two steps from (S)-tert-Butyl3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate in an analogousfashion to that described for the preparation of the racemate3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-22) immediately above. LC-MS (IE, m/z): 251 (M+1)⁺.

Intermediate 23

2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: ethyl 4-bromo-2-ethyl-3-oxobutanoate: To a solution of ethyl2-ethyl-3-oxobutanoate (5.17 g, 32.7 mmol) in water (10 mL) at 0° C. wasadded bromine (1.684 mL, 32.7 mmol) dropwise over 2 h. The resultingsolution was stirred at rt for 16 h. The mixture was extracted withethyl acetate (100 mL) and the organic phase was dried over sodiumsulfate and concentrated to give ethyl 4-bromo-2-ethyl-3-oxobutanoate.¹HNMR (500 MHz, CDCl₃), δ4.327-4.284(m, 2H), 2.412(s, 2H), 2.320-2.212(q, 2H), 1.338-10309 (m, 3H), 1.042-1.013 (t, J=7.3 Hz, 3H).

Step B: 3-ethyl-4-hydroxyfuran-2(5H)-one: A mixture of ethyl4-bromo-2-ethyl-3-oxobutanoate and hydrogen bromide (48%, 0.037 mL,0.327 mmol) was heated at 100° C. for 20 h. After cooling to rt, thesolid was collected by filtration followed by diethyl ether washing togive 3-ethyl-4-hydroxyfuran-2(5H)-one. LC/MS: (M+1)⁺: 129.05.

Step C: 4-ethyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate: Toa solution of 3-ethyl-4-hydroxyfuran-2(5H)-one (400 mg, 3.12 mmol) indichloromethane (10 mL) at −78° C. was added 2,6-lutidine (0.545 mL,4.68 mmol) and triflic anhydride (0.633 mL, 3.75 mmol) dropwise. Thereaction solution was stirred at −78° C. for 1 h before being warmed tort for 2 h. The mixture was diluted in dichloromethane (100 mL) andwashed with 1 N hydrogen chloride (3×100 mL), sodium bicarbonatesolution, dried over sodium sulfate and concentrated to give4-ethyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate. LC/MS:(M+1)⁺: 261.01.

Step D: tert-butyl2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(200 mg, 0.786 mmol),4-ethyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (246 mg,0.944 mmol), Xantphos (45.5, 0.079 mmol), palladium (II) acetate (8.8mg, 0.039 mmol), water (0.043 mL, 2.4 mmol), and potassium carbonate(217 mg, 1.57 mmol) in toluene (20 mL) was heated at 60° C. for 16 h.After filtration through CELITE®, the filtrate was concentrated and theresidue was purified on silica gel using ethyl acetatehexane to give thetitle compound. LC/MS: (M+1)⁺: 365.19.

Step E:2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(0.34 g, 0.93 mmol) in dichloromethane (1 mL) was added trifluoroaceticacid (2.16 mL, 28 mmol) and the resulting solution was stirred at rt for1 h. After removing the volatiles, the residue was dissolved indichloromethane (2 mL) and treated with hydrogen chloride (2 mL, 4 N indioxane) and the mixture was concentrated to give2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one.LC/MS: (M+1)⁺: 265.16.

Intermediate 24

2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: ethyl 4-bromo-2-isopropyl-3-oxobutanoate: To a solution of ethyl2-acetyl-3-methylbutanoate (5.10 g, 29.6 mmol) in water (10 mL) at 0° C.was added bromine (1.53 mL, 29.6 mmol) dropwise over 2 h. Chloroform (30mL) was added and the resulting solution was stirred at rt for 16 h.Ethyl acetate (300 mL) was added to the reaction solution and theorganic phase was dried over sodium sulfate and concentrated to give thetitle compound. ¹HNMR (500 MHz, CDCl₃), δ4.300-4.282 (m, 2H),2.601-2.575 (m, 1H), 2.406 (s, 2H), 1.331-1.303 (t, J=7.1 Hz, 3H),1.085-1.072 (d, J=6.5 Hz, 3H), 1.048-1.035 (d, J=6.7 Hz, 3H).

Step B: 4-hydroxy-3-isopropylfuran-2(5H)-one: A mixture of ethyl4-bromo-2-isopropyl-3-oxobutanoate (7.1 g, 28 mmol) and hydrogen bromide(48%, 0.032 mL, 0.28 mmol) was heated at 100° C. for 8 h. After coolingto rt, the solid was collected by filtration followed by diethyl etherwashing to give 4-hydroxy-3-isopropylfuran-2(5H)-one. LCMS:(M+1)⁺:143.09.

Step C: 4-isopropyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate: To a solution of4-hydroxy-3-isopropylfuran-2(5H)-one (400 mg, 2.81 mmol) in methylenechloride (10 mL) at −78° C. was added 2,6-lutidine (0.492 mL, 4.22 mmol)and triflic anhydride (0.570 mL, 3.38 mmol) dropwise, and the reactiontemperature was maintained at −78° C. for 1 h before warmed to rt for 2h. The mixture was partitioned between methylene chloride and 1 Nhydrogen chloride. The organic phase was washed with 1N hydrogenchloride then diluted sodium bicarbonate, dried over sodium sulfate andconcentrated to give the title compound. LCMS: (M+1)⁺: 275.07.

Step D: tert-butyl2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(I-11) (200 mg, 0.786 mmol), 4-isopropyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (259 mg, 0.944 mmol), Xantphos (46 mg, 0.079mmol), palladium (II) acetate (8.8 mg, 0.039 mmol), water (0.043 mL, 2.4mmol), and potassium carbonate (217 mg, 1.57 mmol) in toluene (20 mL)was heated at 66° C. for 16 h. After filtration through CELITE®, thefiltrate was concentrated and the residue was purified on a silica gelcolumn to give the title compound. LC/MS: (M+1)⁺: 379.21.

Step E:2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(195 mg, 0.515 mmol) in methylene chloride was added trifluoroaceticacid at rt and the resulting solution was stirred at rt for 1 h. Afterremoving the volatiles the residue was dissolved in methylene chlorideand treated with hydrogen chloride (2 mL, 4 N in dioxane) andconcentrated again to give2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneas hydrogen chloride salt. LCMS: (M+1)⁺: 279.16.

Intermediate 25

2-(4-cyclopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-Butyl2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-Butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(I-16, Step A) (784 mg, 2.33 mmol) was dissolved in DCM (20 mL) and wastreated with NBS (498 mg, 2.80 mmol) at 25° C. for 12 hours. Thereaction mixture was diluted with DCM (20 mL), washed with water (20 mL)and brine (20 mL), dried over anhydrous sodium sulfate and filtered. Thefiltrates were concentrated and the crude product was purified by columnchromatography (ISCO 40 g silica gel column), eluting with 50-100% ethylacetatehexane gradient to give the title compound.

Step B: tert-Butyl2-(4-cyclopropyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:In a microwave vial, tert-butyl2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(90 mg, 0.22 mmol) was dissolved in toluene (2 mL) and water (0.2 mL).Potassium phosphate (138 mg, 0.650 mmol), tricyclohexylphosphine (18 mg,0.065 mmol), cyclopropylboronic acid (74.5 mg, 0.867 mmol) and palladiumacetate (4.87 mg, 0.022 mmol) were added. The reaction mixture wasde-gassed and heated at 100° C. for 12 hours. After cooling to roomtemperature, the reaction mixture was concentrated and the resultingresidue was dissolved in EtOAc (50 mL), washed with water (30 mL) andbrine (30 mL), dried over sodium sulfate, and filtered. Removing thesolvent gave crude product that was purified by column chromatographyeluting with 0-100% EtOAc/hexane gradient to yield the title compound.¹H NMR (500 MHz, CDCl₃) δ 5.20 (s, 2H), 4.22 (m, 2H), 3.99 (m, 2H), 3.05(m, 2H), 2.09 (m, 2H), 1.92 (m, 2H), 1.60 (m, 2H), 1.56 (m, 10H), 1.02(m, 2H), 0.82 (m, 2H).

Step C:2-(4-cyclopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:The title compound can be prepared in a similar fashion to thatdescribed for2-(4-isopropyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-24) above using TFA.

Intermediate 26

2-(2-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: ethyl 4-bromo-3-oxopentanoate: To a solution of ethyl3-oxopentanoate (5.00 g, 34.7 mmol) in chloroform (27 mL) at 0° C. wasadded bromine (1.79 mL, 34.7 mmol) in chloroform (10 mL) drop-wise. Theresulting solution was stirred at rt for 16 h. The solution was washedwith water, dried over sodium sulfate, concentrated to give ethyl4-bromo-3-oxopentanoate. ¹HNMR (500 MHz, CDCl₃), δ4.670-4.630 (dd, J=6.7Hz, 1H), 4.251-4.208(dd, J=7.2 Hz, 2H), 3.883-3.851(d, J=16 Hz, 1H),3.687-3.655(d, J=16 Hz, 1H), 1.804-1.791 (d, J=6.8 Hz, 3H), 1.323-1.295(m, J=7.2 Hz, 3H).

Step B: 4-hydroxy-5-methylfuran-2(5H)-one: Ethyl 4-bromo-3-oxopentanoate(7.49 g, 33.6 mmol) was treated with potassium hydroxide (5.03 g, 90mmol) in water (36 mL) at 0° C. The resulting mixture was vigorouslystirred at 0° C. for 4 h. The reaction mixture was extracted withmethylene chloride (twice with 100 mL). The alkaline phase was acidifiedto pH<1 by 6N hydrogen chloride. The acidic phase was extracted withmethylene chloride (3×100 mL). The latter combined organic phase wasdried over sodium sulfate and concentrated to give the title compound.¹HNMR (500 MHz, CDCl₃), δ5.064 (s, 1H), 4.949-4.878(m, 1H), 3.251-3.239(m, 1H), 1.566-1.547 (m, 3H).

Step C: 2-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate:To a solution of 4-hydroxy-5-methylfuran-2(5H)-one in methylene chloride(10 mL) at −78° C. was added 2,6-lutidine (0.612 mL, 5.26 mmol) andtriflic anhydride (0.711 mL, 4.21 mmol) drop-wise. The reactiontemperature was maintained at −78° C. for 0.5 h before being warmed tort for 1 h. The mixture was washed with hydrogen chloride (1N, threetimes 100 mL), diluted sodium bicarbonate and dried over sodium sulfateto give the title compound. LC/MS: (M+1)⁺: 247.00.

Step D: tert-butyl2-(2-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(200 mg, 0.786 mmol),2-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (232 mg,0.944 mmol), Xantphos (45.5 mg, 0.079 mmol), palladium (II) acetate(8.83 mg, 0.039 mmol), water (0.043 mL, 2.359 mmol), and potassiumcarbonate (217 mg, 1.573 mmol) in toluene (20 mL) was degassed bynitrogen and heated at 65° C. for 16 h. After filtration through CELITE®the filtrate was concentrated and the residue was purified on silica gelcolumn using ethyl acetate and hexane as eluting solvents to give thetitle compound. LCMS: (M+1)⁺: 351.15.

Step E:2-(2-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(2-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(127 mg, 0.362 mmol) in methylene chloride (1 mL) was addedtrifluoroacetic acid (1.396 mL, 18.12 mmol), the resulting solution wasstirred at rt for 1 h. After concentration, the residue was treated withmethylene chloride (1 mL) and hydrogen chloride (1 mL, 4 N in dioxane).The resulting mixture was concentrated to give the title compound ashydrogen chloride salt. LC/MS: (M+1)⁺: 251.19.

Intermediate 27

2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: ethyl 4-bromo-2-methyl-3-oxopentanoate: To a solution of ethyl2-methyl-3-oxopentanoate (5.0 g, 34.7 mmol) in chloroform at 0° C. wasadded bromine (1.79 mL, 34.7 mmol) in chloroform (10 mL) drop-wise. Theresulting solution was stirred at rt for 16 h. The solution was washedwith water, dried over sodium sulfate, and concentrated to give thetitle compound. ¹HNMR (500 MHz, CDCl₃), δ4.781-4.740 (dd, J=6.6 Hz, 1H),4.140-4.098(dd, J=7.0 Hz, 1H), 3.770 (s, 3H), 1.797-1.783(d, J=6.6 Hz,3H), 1.455-1.442 (d, J=7.0 Hz, 3H).

Step B: 4-hydroxy-3,5-dimethylfuran-2(5H)-one: To ethyl4-bromo-2-methyl-3-oxopentanoate (7.49 g, 31.6 mmol) was added coldpotassium hydroxide (4.7 g, 84 mmol) in water (36 mL) at 0° C., theresulting mixture was vigorously stirred at 0° C. for 4 h. The reactionmixture was extracted with methylene chloride (2×100 mL), the alkalinephase was acidified to ph 1 by 6N hydrogen chloride followed byextraction with methylene chloride (3 times 100 mL). The combined latterorganic phase was dried over sodium sulfate, and concentrated to give4-hydroxy-3,5-dimethylfuran-2(5H)-one. LCMS: (M+23)⁺: 151.10, ¹HNMR (500MHz, CDCl₃), δ4.882-4.842 (dd, J=6.8 Hz, 1H), 3.744 (s, 1H), 1.759(s,3H). 1.526-1.513 (d, J=6.8 Hz, 3H).

Step C: 2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate: To a solution of4-hydroxy-3,5-dimethylfuran-2(5H)-one (400 mg, 3.12 mmol) in methylenechloride (10 mL) at −78° C. was added 2,6-lutidine (0.545 mL, 4.68 mmol)and triflic anhydride (0.633 mL, 3.75 mmol) drop-wise. The reactiontemperature was maintained at −78° C. for 1 h before warming to rt for 2h. The mixture was diluted in methylene chloride (100 mL) and washedwith 1N hydrogen chloride (3×100 mL) and diluted sodium bicarbonate,then dried over sodium sulfate and concentrated to give the titlecompound. LCMS: (M+1)⁺: 261.00.

Step D: tert-butyl2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(200 mg, 0.786 mmol), 2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate, Xantphos (45.5 mg, 0.079 mmol), water (0.043mL, 2.4 mmol) and potassium carbonate (217 mg, 1.57 mmol) in toluene (20mL) was degassed by nitrogen for 20 min followed by addition ofpalladium acetate (8.8 mg, 0.039 mmol). The resulting mixture was heatedat 65° C. for 16 h. After filtration the filtrate was concentrated andthe residue was purified on silica gel column eluting with EtOAc/hexaneto give the title compound. LC/MS: (M+1)⁺: 365.20.

Step E:2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(195 mg, 0.535 mmol) in methylene chloride (1 mL) was addedtrifluoroacetic acid (2.06 mL, 26.8 mmol) and the resulting solution wasstirred at rt for 1 h. After removing the volatiles the residue wasdissolved in methylene chloride (1 mL) and treated with hydrogenchloride (4 mL, 1N in diethyl ether) and concentrated to give2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one.LCMS: (M+1)⁺: 265.19.

Intermediate 28

2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-butyl2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:To a solution of tert-butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(I-16, Step A) (2.1 g, 6.2 mmol) in chloroform (50 mL) was added NCS(1.00 g, 7.49 mmol) at rt and the resulting solution was heated at 60°C. overnight. After removing the volatiles the residue was purified onsilica gel column using EtOAc/hexane as eluting solvents to give thetitle compound. LCMS: (M+1)⁺: 371.11, 372.99.

Step B:2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(2.26 g, 6.09 mmol) in methylene chloride (10 mL) was addedtrifluoroacetic acid (9.39 mL, 122 mmol) and the resulting solution wasstirred at rt for 1 h. After removing the volatiles, the residue waspartitioned between methylene chloride (100 mL) and 1N sodium hydroxide(100 mL). The alkaline phase was extracted with methylene chloride(2×100 mL). The combined organic phase was dried over sodium sulfate andconcentrated to give2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one.LCMS: (M+1)⁺: 271.07, 272.96.

Intermediate 29

2-(4-fluoro-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: 3-bromo-4-ethoxy-3-fluoro-4-hydroxydihydrofuran-2(3H)-one: To asolution of 4-hydroxyfuran-2(5H)-one (2.25 g, 22.5 mmol) in ethanol (20mL) was added NBS (4.00 g, 22.5 mmol), and the resulting solution wasstirred at rt for 40 min. Then1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octanebis(tetrafluoroborate) (7.97 g, 22.5 mmol) was added and the resultingmixture was stirred at rt overnight. After filtration and concentration,the residue was purified on silica gel column using EtOAc/hexane aseluting solvents to afford the title compound. ¹HNMR (500 MHz, CDCl₃),δ4.322-4.303 (m, J=7.0 Hz, 2H), 3.879-3.788 (m, 2H), 1.356-1.328 (t,J=7.0 Hz, 3H).

Step B: 3-fluoro-4-hydroxyfuran-2(5H)-one: To a solution of3-bromo-4-ethoxy-3-fluoro-4-hydroxydihydrofuran-2(3H)-one (4.39 g, 18.1mmol) in tetrahydrofuran (20 mL) was added tri-n-butyltin hydride (9.39mL, 35.0 mmol) at 0° C. under N₂. The resulting solution was stirred atrt overnight. After removing the volatiles, the residue was stirred in30 mL 50% acetic acid and 30 mL hexane at rt for 30 min. The acidicphase was washed with hexane (3×30 mL) before concentration. The residewas dissolved in sodium carbonate (50 mL, 2N), extracted with 40%EtOAc/hexane (4×50 mL), the alkaline phase was acidified to pH <1 by 1 Nhydrogen chloride. The acidic phase was then extracted with ethylacetate (8 times 60 mL). The combined organic phase was dried oversodium sulfate, concentrated to give 3-fluoro-4-hydroxyfuran-2(5H)-one.¹HNMR (500 MHz, DMSO-d₆), δ4.694-4.687 (d, J=3.9 Hz, 2H).

Step C:4-fluoro-2-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate:To a solution of 3-fluoro-4-hydroxyfuran-2(5H)-one (400 mg, 3.39 mmol)in methylene chloride (10 mL) at −78° C. was added 2,6-lutidine (0.592mL, 5.08 mmol) and triflic anhydride (0.687 mL, 4.07 mmol) drop-wise,the reaction temperature was maintained at −78° C. for 1 h before warmedto rt for 2 h. The mixture was washed with 1 N hydrogen chloride (3times 100 mL), and diluted sodium bicarbonate solution, dried oversodium sulfate, concentrated to give the title compound. ¹HNMR (500 MHz,CDCl₃), δ4.986-4.974(d, J=6.0 Hz, 2H).

Step D: tert-butyl2-(4-fluoro-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:A mixture of tert-butyl 1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(150 mg, 0.590 mmol), 4-fluoro-2-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (148 mg, 0.590 mmol), xantphos (34.1 mg, 0.059mmol), water (0.032 mL, 1.77 mmol) in toluene (20 mL) was degassed bynitrogen followed by addition of palladium acetate (6.6 mg, 0.029 mmol).The resulting mixture was heated at 65° C. overnight. After filtrationthrough CELITE®, the filtrate was concentrated and the residue waspurified on silica gel column using ethyl acetate and hexane as elutingsolvents to give the title compound. LCMS: (M+1)⁺: 355.15.

Step E:2-(4-fluoro-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of tert-butyl2-(4-fluoro-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(109 mg, 0.308 mmol) in methylene chloride (1 mL) was addedtrifluoroacetic acid (1.896 mL, 24.61 mmol) and the resulting solutionwas stirred at rt for 1 h. After removing the volatiles, the residue wasdissolved in methanol and loaded onto an ion exchange column. Afterwashing with methanol, the product was eluted with 2N ammonia inmethanol solution which was concentrated to give the title compound.LC/MS: (M+1)⁺: 255.09.

Intermediate 30

(1R,3r,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one

Step A: (1R,3s,5S)-8-tert-butyl 3-methyl8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To a solution of(1R,3s,5S)-8-(tert-butoxycarbonyl)-8-azabicyclo[3.2.1]octane-3-carboxylicacid (5.00 g, 19.6 mmol) in a mixture solvent of dry MeOH (60 mL) andDCM (60.0 mL) was added (trimethylsilyl)diazomethane (19.6 mL, 39.2mmol). The mixture was stirred for 0.5 hr. AcOH (5 mL) was added. Thevolatiles were removed under reduced pressure. The residue was dissolvedin EtOAc, and the solution was washed with saturated NaHCO₃ and brine,and dried over MgSO4. The solvent was removed to give a solid which wasused in the next step without further purification. LC-MS: 214.10(M+1−56).

Step B: (1R,3r,5S)-8-tert-butyl 3-methyl3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To asolution of (1R,3r,5S)-8-tert-butyl 3-methyl8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (5.00 g, 18.6 mmol) in THF(100 mL) was added LDA (13.9 mL, 27.8 mmol) at −78° C. The mixture wasstirred at the same temperature for 30 min, then bromoacetonitrile (1.94mL, 27.8 mmol) in THF (15 mL) was added by injection. The mixture wasstirred at −78° C. for 15 min, quenched with saturated KHSO₄ at −78° C.,warmed up to rt and diluted with ether (100 mL). The organic layer wasseparated, and the aqueous was extracted with ether (50 mL). Thecombined organic layers were washed with brine, dried (MgSO₄), andconcentrated. The residue was purified by column (silica gel 120 g,EtOAc-Hexane-0-50% gradient, then 50% EtOAc. ¹H-NMR (500 MHz, CDCl₃): δppm 4.18 (1 H, m), 4.27 (1 H, m), 3.83 (3 H, s), 2.58 (2 H, m), 2.43 (2H, m), 1.55-1.95 (6 H, m), 1.50 (9 H, s). LC-MS 209.23 (M+1−100).

Step C: (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-aminoethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To asolution of (1R,3r,5S)-8-tert-butyl 3-methyl3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (4.0 g,12.97 mmol) in ethanol (20 mL) and AcOH (20 mL) was added platinum(IV)oxide (0.295 g, 1.30 mmol). The mixture was hydrogenated on a shaker (45psi hydrogen) for 24 hr. The catalyst was filtered off through a CELITE®pad, and the filtrate was concentrated. The crude material was used inthe next step without further purification. LC-MS: 313.20 (M+1), 257.18(M+1−56).

Step D: (1R,3r,5S)-tert-butyl2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate:A mixture of (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-aminoethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (4.2 g,13.4 mmol) and potassium carbonate (9.29 g, 67.2 mmol) in MeOH (50 mL)was heated at 60° C. for 1 hr. The mixture was concentrated, and DCM (50mL) was added. The suspension was filtered through a silica gel pad. Thefiltrate was concentrated to give a solid which was directly used in thenext step ¹H-NMR (500 MHz, CDCl₃): δ ppm 5.95 (1 H, bs), 4.30 (1 H, m),4.20 (1 H, m), 3.26 (2 H, t, J=7.0 Hz), 1.75-2.15 (6 H, m), 1.47 (9 H,s). LCMS: 281.15 (+1), 225.14 (M+1−56).

Step E: (1R,3r,5S)-tert-butyl1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate:A mixture of4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (1.861 g,7.56 mmol), (1R,3r,5S)-tert-butyl2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate(1.63 g, 5.81 mmol), palladium(II) acetate (0.065 g, 0.291 mmol),4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.336 g, 0.581 mmol),potassium carbonate (2.411 g, 17.44 mmol) and water (0.314 mL, 17.4mmol) in toluene (150 mL) was heated at 60° C. under N₂ overnight. Themixture was diluted with EtOAc. Solid was filtered off through a CELITE®pad, and the filtrate was concentrated. The residue was purified bycolumn (80 g silica gel, 0-100% of EtOAc in hexane, then 100% EtOAc).LCMS: 377.12 (M+1).

Step F:(1R,3r,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one:A solution of (1R,3r,5S)-tert-butyl1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylatein DCM (50 mL) and TFA (10 mL) was stirred at rt for 1 h. Volatiles wereremoved under reduced pressure. The residue was dissolved in methanol,and was loaded on a Bond Elut SCX column after the column was washedwith 20 mL methanol. The column with the desired compound was elutedwith methanol to remove TFA (˜20 mL), and the free base of the desiredcompound was eluted out with 2N NH₃ in methanol (˜20 mL). The solutionwas concentrated to give a free base (solid). ¹H-NMR (500 MHz, CDCl₃): δppm 5.25 (2 H, s), 3.95 (2 H, t, J=6.9 Hz), 3.73 (2 H, m), 2.15 (4 H,m), 2.07 (3 H, s), 2.05 (4 H, m), 1.85 (2 H, m). LCMS 277.10 (M+1).

Intermediate 31

(1R,3r,5S)-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one:The title compound was prepared in an analogous fashion to thatdescribed for(1R,3r,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one,except in Step E, where 4-bromofuran-2-one was used in place of4-methyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate. LCMS:263 (M+1).

Intermediate 32

(1R,3s,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one

Step A: (1R,5S,Z)-tert-butyl3-(1-cyano-2-methoxy-2-oxoethylidene)-8-azabicyclo[3.2.1]octane-8-carboxylate:Methyl 2-cyanoacetate (3.63 g, 36.6 mmol), commercially available(1R,5S)-tert-butyl 3-oxo-8-azabicyclo[3.2.1]octane-8-carboxylate (5.5 g,24.41 mmol), ammonium acetate (2.51 mL, 36.6 mmol), acetic acid (5.59mL, 98 mmol) and toluene (100 mL) were placed in a 500-mL round-bottomedflask attached to a Dean-Stark constant water separator which wasconnected to a reflux condenser. The flask was heated in an oil bath at150° C., and the water that distilled out of the mixture with therefluxing toluene was removed from the separator at intervals(overnight). Solvent was removed under reduced pressure. The residue wasdissolved in EtOAc (150 mL). The solution was washed with brine, dried(MgSO₄), and concentrated. The residue was purified by columnchromatography on silica gel (hexane in EtOAc 0-60% gradient). ¹H-NMR(500 MHz, CDCl₃): δ ppm 4.40 (2 H, m), 3.86 (3 H, m), 2.75 (2 H, m),2.55 (2 H, m), 2.06 (2 H, m), 1.57 (2 H, m), 1.50 (9 H, s).LC-MS-250.99.12 (M+1−56).

Step B: (1R,3r,5S)-tert-butyl3-(1-cyano-2-methoxy-2-oxoethyl)-3-vinyl-8-azabicyclo-[3.2.1]octane-8-carboxylate:To a suspension of (1R,5S,Z)-tert-butyl3-(1-cyano-2-methoxy-2-oxoethylidene)-8-azabicyclo[3.2.1]octane-8-carboxylate(7.17 g, 23.4 mmol) and copper(I) iodide (2.229 g, 11.70 mmol) in THF(150 mL) was added vinylmagnesium bromide (35.1 mL, 35.1 mmol) byinjection at −10° C. The mixture was stirred at the same temperature for1 h. The reaction was quenched with saturated ammonium acetate aqueous,and the mixture was diluted with EtOAc (100 mL). The organic layer wasseparated, and the aqueous layer was extracted with EtOAc (100 mL). Thecombined organic layers were washed with brine, dried over MgSO₄ andconcentrated. The crude material was purified by column chromatographyon silica gel (eluted with 0-50% EtOAc, then 50% EtOAc in hexane).¹H-NMR (500 MHz, CDCl₃): δ ppm 5.82 (1 H, dd, J₁=17.3 Hz, J₂=10.7 Hz),5.15 (1 H, d, J=10.7 Hz), 5.10 (1 H, d, J=17.3 Hz), 4.20-4.50 (2 H, m),3.85 (1 H, s), 3.81 (3 H, s), 2.17-2.35 (2 H, m), 1.90-2.15 (4 H, m),1.58-1.72 (2 H, m) m 1.47 (9 H, s). LC-MS: 278.92 (M+1−56).

Step C: (1R,3s,5S)-tert-butyl3-(cyanomethyl)-3-vinyl-8-azabicyclo[3.2.1]octane-8-carboxylate: Asuspension of (1R,3r,5S)-tert-butyl3-(1-cyano-2-methoxy-2-oxoethyl)-3-vinyl-8-azabicyclo[3.2.1]octane-8-carboxylate(7.2 g, 21.53 mmol) and sodium chloride (1.258 g, 21.53 mmol) in DMSO(40 mL) and water (4 mL) was heated in an 160° C. oil bath for 2 h, thencooled down to RT. Water (50 mL) was added, and the mixture wasextracted with ethyl ether (twice with 50 mL). The combined ether layerswere washed with brine, dried over MgSO₄, and concentrated under reducedpressure. The crude material was purified by column chromatography(0-70% ethyl acetate in hexane). ¹H-NMR (500 MHz, CDCl₃): δ ppm 5.73 (1H, dd, J1=17.7 Hz, J2=11.0 Hz), 5.10 (1 H, d, J=11 HZ), 5.08 (1 H, d,J=17.7 Hz), 5.30 (2 H, m), 2.70 (2 H, s), 1.95-2.12 (4 H, m), 1.70 (4 H,m), 1.45 (9 H, s). LC-MS: 221.11 (M+1−56).

Step D: (1R,3s,5S)-tert-butyl3-(cyanomethyl)-3-formyl-8-azabicyclo[3.2.1]octane-8-carboxylate: To asuspension of (1R,3s,5S)-tert-butyl3-(cyanomethyl)-3-vinyl-8-azabicyclo[3.2.1]octane-8-carboxylate (4.00 g,14.5 mmol, water (15 mL) and sodium periodate (12.4 g, 57.9 mmol) indioxane (45 mL) was added osmium tetroxide (0.184 g, 0.724 mmol). Thesuspension was stirred for 17 hr at rt. The mixture was made acidic with1N hydrochloric acid, diluted with EtOAc (50 mL). The organic layer wasseparated, washed with brine, dried over MgSO₄, and concentrated underreduced pressure. The residue was used without further purification.¹H-NMR (500 MHz, CDCl₃): δ ppm 9.14 (1 H, s), 4.17 (2 H, m), 3.80 (3 H,s), 2.32 (2 H, m), 2.15 (2 H, m), 1.73 (2 H, m), 1.55 (2 H, m).LC-MS-223.16 (M+1−56).

Step E: (1R,3s,5S)-8-(tert-butoxycarbonyl)-3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3-carboxylicacid: To a solution of (1R,3s,5S)-tert-butyl3-(cyanomethyl)-3-formyl-8-azabicyclo[3.2.1]octane-8-carboxylate (5.10g, 18.3 mmol) in t-BuOH/H₂O (2:1) was added sodium dihydrogenphosphatehydrate (7.59 g, 55.0 mmol) and 2-methylbut-2-ene (9.7 mL, 92 mmol). Thesuspension was cooled to 0° C., and sodium chlorite (4.97 g, 55.0 mmol)was added portion-wise. The reaction mixture was stirred at 0° C. for 1h, acidified with 1M HCl, extracted with CHCl₃:2-propanol (3:1), dried(Na₂SO₄) and concentrated. The crude material was heated with aDean-Stark apparatus at reflux in toluene to dry. Hot toluene solutionwas separated from solid, and the solution was concentrated to obtainthe title compound. LCMS 239.23 (M+1−56), 295.23 (+1)

Step F (1R,3s,5S)-8-tert-butyl 3-methyl3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To asolution of(1R,3s,5S)-8-(tert-butoxycarbonyl)-3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3-carboxylicacid (5.20 g, 17.7 mmol) in a mixture of MeOH (30 mL) and DCM (30 mL)was slowly added (trimethylsilyl)diazomethane (13.3 mL, 26.5 mmol) atrt. The mixture was stirred at the same temperature for 0.5 h. Aceticacid (˜5 mL) was added to remove excess of (trimethylsilyl)diazomethane.The solution was concentrated, and the residue was used directly in thenext step. ¹H-NMR (500 MHz, CDCl₃): δ ppm 4.32 (2 H, m), 3.74 (3 H, s),2.85 (2 H, s), 2.65 (2 H, m), 2.08 (2 H, m), 1.65 (4 H, m), 1.42 (9 H,s). LCMS: 253 (M+1−56).

Step G: (1R,3s,5S)-8-tert-butyl 3-methyl3-(2-aminoethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: A mixtureof (1R,3s,5S)-8-tert-butyl 3-methyl3-(cyanomethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (3.5 g, 11.4mmol) and platinum(iv) oxide (0.258 g, 1.14 mmol) in ethanol (20 mL) andAcOH (20 mL), was hydrogenated on a shaker (45 psi hydrogen) at rt for48 hr. The catalyst was filtered off through a CELITE® pad. Thefiltration was concentrated and the residue was used directly in thenext step. LCMS 313.25 (+1), 257.25 (+1−56).

Step H: (1R,3s,5S)-tert-butyl2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate:A mixture of (1R,3s,5S)-8-tert-butyl 3-methyl3-(2-aminoethyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (3.50 g,11.2 mmol) and potassium carbonate (7.74 g, 56.0 mmol) in MeOH (50 mL)was heated at 60° C. for 1 hr. The mixture was concentrated, and DCM (50mL) was added. The suspension was filtered through a silica gel pad, andthe filtrate was concentrated to give a solid which was directly used inthe next step. ¹H-NMR (500 MHz, CDCl₃): δ ppm 6.43 (1 H, bs), 4.25 (1 H,m), 4.37 (1 H, m), 3.32 (2 H, t, J=7.0 Hz), 2.24 (2 H, m), 2.35 (2 H,m), 1.97 (2 H, m), 1.82 (2 H, m), 1.45 (9 H, s), 1.46 (2 H, m). LCMS:281 (M+1), 225 (M+1−56).

Step I: (1R,3s,5S)-tert-butyll′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate:A mixture of (1R,3s,5S)-tert-butyl2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate(2.00 g, 7.13 mmol), 4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (1.93 g, 7.85 mmol), diacetoxypalladium (0.080g, 0.36 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine)(0.413 g, 0.713 mmol), potassium carbonate (2.96 g, 21.4 mmol) and water(0.386 g, 21.40 mmol) in toluene (100 mL) was heated at 60° C. under N₂for 4 hr. The mixture was diluted with EtOAc (50 mL). The solid wasfiltered off through a CELITE® pad, and the filtrate was concentrated.The residue was purified by column chromatography (0-100% of EtOAc inhexane, then 100% EtOAc) to provide the title compound. LC-MS 321.03(+1−56), 377.03 (+1).

Step J:(1R,3s,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one:(1R,3s,5S)-tert-butyl2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylatewas stirred with TFA (5 mL) in DCM (30 mL) at rt for 1 h. Volatiles wereremoved under reduced pressure. The residue was dissolved in methanol,and was loaded onto a Bond Elut SCX column (ion exchange) after thecolumn was washed with 20 mL methanol. The column with the desiredcompound was eluted with methanol to remove TFA (˜20 mL), the free baseof the desired compound was eluted out with 2N NH₃ in methanol (˜20 mL).The solution was concentrated to give the title compound as a free base(solid). ¹H-NMR (500 MHz, CDCl₃): δ ppm 5.25 (1 H, s), 4.00 (2 H, t,J=6.9 Hz), 3.67 (2 H, m), 2.42 (2 H, t, J=6.9 Hz), 2.06 (3 H, s), 2.04(2 H, m), 1.97 (2 H, m), 1.82 (2 H, m). LCMS 277.03(M+1), 321.03(M+1−56).

Intermediates 33A and 33B

(1R,3r,5S)-5′-methyl-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one(Isomers A and B)

Step A: (1R,3r,5S)-8-tert-butyl 3-methyl8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To a solution ofcommercially available(1R,3r,5S)-8-(tert-butoxycarbonyl)-8-azabicyclo[3.2.1]octane-3-carboxylicacid (10.0 g, 39.2 mmol) and methanol (4.75 mL, 118 mmol) in methylenechloride (200 mL) was added EDC (11.3 g, 58.8 mmol),diisopropylethylamine (13.7 mL, 78 mmol) and DMAP (0.479 g, 3.92 mmol).The resulting solution was stirred at rt for 16 h. The reaction solutionwas washed with potassium bisulfate (1 N, 200 mL), water (200 mL),saturated sodium bicarbonate, dried over sodium sulfate, andconcentrated to give the title compound. LCMS: (M+1)⁺: 270.1.

Step B: (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-methylallyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To asolution of diisopropylamine (5.94 mL, 41.7 mmol) in tetrahydrofuran (5mL) at 0° C. was added n-butyllithium (16.7 mL, 41.7 mmol) drop-wise,and the resulting solution was stirred at 0° C. for 0.5 h. This solutionwas added dropwise to a solution of the compound of Step A (7.48 g, 27.8mmol) in tetrahydrofuran (90 mL) at −78° C. The resulting solution wasstirred at −78° C. for 1 h and then 3-bromo-2-methylpropene (4.03 mL,40.0 mmol) was added dropwise. After stirring at −78° C. for 1.5 h, thereaction was quenched by addition of saturated ammonium acetate. Themixture was diluted with ethyl acetate, washed with saturated ammoniumacetate twice, dried over sodium sulfate, concentrated and the residuewas purified on silica gel column using ethyl acetatehexane as elutingsolvents to give the title compound. LCMS: (M+1)⁺: 324.3.

Step C: (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-oxopropyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate: To asolution of (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-methylallyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (7.99 g,24.7 mmol) in dioxane (100 mL) and water (50 mL) was added sodiumperiodate (10.6 g, 49.4 mmol) and osmium tetroxide (0.126 g, 0.494mmol). The resulting mixture was stirred at rt for 18 h and then sodiumthiosulfate (1 g) was added. After stirring at rt for 0.5 h, the mixturewas filtered and the filtrate was concentrated. The residue wasdissolved in ethyl acetate (300 mL) and washed with brine, dried oversodium sulfate and concentrated. This residue was purified on silica gelusing ethyl acetate and hexane as eluting solvents to give the titlecompound. LC/MS: (M+1)⁺: 326.2.

Step D: (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate:To a solution of (1R,3r,5S)-8-tert-butyl 3-methyl3-(2-oxopropyl)-8-azabicyclo[3.2.1]octane-3,8-dicarboxylate (7.90 g,24.3 mmol) in methanol (50 mL) was added magnesium sulfate (5.84 g, 48.6mmol), ammonium acetate (3.74 g, 48.6 mmol), and sodium cyanoborohydride(3.05 g, 48.6 mmol). The resulting mixture was heated at 80° C. in asealed tube for 18 h. After cooling to rt, the mixture was filtered andthe filtrate was concentrated and the residue was partitioned betweenmethylene chloride and saturated sodium bicarbonate. The aqueous phasewas extracted with methylene chloride, the combined organic phase wasdried over sodium sulfate, concentrated and the residue was purified onsilica gel using ethyl acetate as eluting solvent to give the titlecompound. LCMS: (M+1)⁺: 295.3.

Step E: (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate,Isomer (A) and Isomer (B): To a solution of (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate(2.41 g, 8.19 mmol) in toluene (30 mL) was added 3-bromo-furanone (1.60g, 9.82 mmol), Xantphos (0.474 g, 0.819 mmol), potassium carbonate(2.263 g, 16.37 mmol), water (0.442 g, 24.6 mmol), and palladium acetate(0.092 g, 0.409 mmol). The resulting mixture was flushed with nitrogenfor 30 min and then heated at 65° C. for 16 h. After cooling to rt, themixture was filtered and the filtrate was concentrated and the residuewas purified on silica gel using ethyl acetate and hexane as elutingsolvents to give the racemate (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylate(LC/MS: (M+1)⁺: 377.05). The racemate was separated on a chiral AScolumn (30×250 mm) using methanol/acetonitrile/carbon dioxide to give:Isomer (A), faster eluting enantiomer; LC/MS: (M+1)⁺: 377.04, and Isomer(B) the slower eluting enantiomer; LC/MS: (M+1)⁺: 377.03.

Step F:(1R,3r,5S)-5′-methyl-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-oneIsomer A and Isomer B: TFA (3.27 mL, 42.5 mmol) was added to a solutionof (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylateIsomer (A) (0.80 g, 2.1 mmol) in methylene chloride (5 mL) and theresulting solution was stirred at rt for 1 h. After removing thevolatiles, the residue was dissolved in methanol (5 mL) and basified tofree base on an ion-exchange column washed with methanol first followedby washing with 1N ammonia in methanol to give Isomer (A) of the titlecompound: LC/MS: (M+1)⁺: 277.07. TFA (3.27 mL, 42.5 mmol) was added to asolution of (1R,3r,5S)-tert-butyl5′-methyl-2′-oxo-1′-(5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidine]-8-carboxylateisomer Isomer (B) (0.8 g, 2.13 mmol) in methylene chloride (5 mL) andthe resulting solution was stirred at rt for 1 h. After removing thevolatiles, the residue was dissolved in methanol (5 mL) and basified tofree base on an ion-exchange column washed with methanol first followedby washing with 1N ammonia in methanol to give Isomer B of the titlecompound. LC/MS: (M+1)⁺: 377.07

Intermediate 34

(1R,3′s,5S)-3-methyl-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-3,9-diazaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidin-]-2′-one

Step A: (1R,5S)-tert-butyl3-methyl-7-(((trifluoromethyl)sulfonyl)oxy)-3,9-diazabicyclo[3.3.1]non-6-ene-9-carboxylate:To a solution of commercially available (1R,5S)-tert-butyl3-methyl-7-oxo-3,9-diazabicyclo[3.3.1]nonane-9-carboxylate (10.0 g, 39.3mmol) in tetrahydrofuran (100 mL) was added LDA solution (23.6 mL, 47.2mmol) at −78° C. drop-wise. The resulting solution was stirred at −78°C. for 0.5 h before being added to a solution of2-[N,N-bis(trifluoromethanesulfonyl)amino]-5-chloropyridine (18.5 g,47.2 mmol) in tetrahydrofuran (25 mL). The resulting solution wasstirred at −78° C. for 2 h, then warmed to rt for 20 min before beingquenched by addition of saturated ammonium chloride and ethyl acetate.The organic phase was washed with saturated sodium bicarbonate, driedover sodium sulfate, filtered, and concentrated and the residue waspurified on silica gel using ethyl acetate and hexane as elutingsolvents to give the title compound. LC/MS: (M+1)⁺: 386.94.

Step B: (1R,5S)-9-tert-butyl 7-methyl3-methyl-3,9-diazabicyclo[3.3.1]non-6-ene-7,9-dicarboxylate: To asolution of (1R,5S)-tert-butyl3-methyl-7-(((trifluoromethyl)sulfonyl)oxy)-3,9-diazabicyclo[3.3.1]non-6-ene-9-carboxylate(14 g, 36 mmol) and diisopropylethylamine (9.47 mL, 54.3 mmol) inmethanol (100 mL) and DMF (100 mL) was triphenylphosphine (0.95 g, 3.62mmol) and palladium (II) acetate (0.407 g, 1.81 mmol). The mixture wasstirred under carbon monoxide atmosphere for 24 h. The mixture wasconcentrated and then partitioned between ethyl acetate and water. Theorganic phase was washed with brine, dried over sodium sulfate,concentrated and the residue was purified on silica gel using ethylacetate and hexane as eluting solvents to give the title compound.LC/MS: (M+1)⁺: 297.2.

Step C: (1R,5S)-9-tert-butyl 7-methyl3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate: To a solutionof (1R,5S)-9-tert-butyl 7-methyl3-methyl-3,9-diazabicyclo[3.3.1]non-6-ene-7,9-dicarboxylate (4.69 g,15.8 mmol) in methanol (50 mL) was added palladium on carbon (10%, 1.684g, 1.583 mmol) and the resulting mixture was subjected to hydrogenationunder 40 psi for three days. After filtration through CELITE® undernitrogen the filtrate was concentrated to give the title compound.LC/MS: (M+1)⁺: 299.1.

Step D: (1R,5S,7 s)-9-tert-butyl 7-methyl7-(cyanomethyl)-3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate:To a solution of diisopropylamine (3.28 mL, 23.02 mmol) intetrahydrofuran (5 mL) was added n-butyllithium (11.51 mL, 23.02)dropwise at 0° C., and the resulting solution was stirred at 0° C. for0.5 h. To a solution of (1R,5S)-9-tert-butyl 7-methyl3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate (4.58 g, 15.35mmol) in tetrahydrofuran (50 mL) at −78° C. was added the above LDAsolution drop-wise. After stirring at −78° C. for 1 h, bromoacetonitrile(1.54 mL, 22.1 mmol) was added drop-wise and the resulting solution wasstirred at −78° C. for 1 h before quenching by addition of saturatedammonium chloride. The mixture was extracted with ethyl acetate. Thecombined organic phase was dried over sodium sulfate, concentrated andthe residue was purified on silica gel using methanol anddichloromethane as eluting solvents to give the title compound. LC/MS:(M+1)⁺: 338.2.

Step E: (1R,5S,7 s)-9-tert-butyl 7-methyl7-(2-aminoethyl)-3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate:To a solution of (1R,5S,7 s)-9-tert-butyl 7-methyl7-(cyanomethyl)-3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate(4.39 g, 13.0 mmol) in methanol (30 mL) was added platinum (IV) oxide(0.207 g, 0.911 mmol) and the resulting mixture was hydrogenated at 40psi for 16 h. After filtration through CELITE® under nitrogen, thefiltrate was concentrated to give the title compound. LC/MS: (M+1)⁺:342.2.

Step F: (1R,3′s,5S)-tert-butyl3-methyl-2′-oxo-3,9-diazaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate:To a solution of (1R,5S,7s)-9-tert-butyl 7-methyl7-(2-aminoethyl)-3-methyl-3,9-diazabicyclo[3.3.1]nonane-7,9-dicarboxylate(4.44 g, 13.0 mmol) in methanol (100 mL) was added potassium carbonate(10.8 g, 78 mmol), and the resulting solution was heated at reflux for 8h. After cooling to rt the mixture was filtered and the filtrate wasconcentrated and the residue was dissolved in methylene chloride (200mL) and dried over sodium sulfate, and concentrated to give the titlecompound. LC/MS: (M+1)⁺: 310.26.

Step G: (1R,3′s,5S)-tert-butyl3-methyl-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-3,9-diazaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate:A mixture of (1R,3's,5S)-tert-butyl3-methyl-2′-oxo-3,9-diazaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate(4.0 g, 12.9 mmol),4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (3.82 g,15.5 mmol), Xantphos (0.748 g, 1.29 mmol), and potassium carbonate (3.57g, 25.9 mmol) in toluene (100 mL) was degassed with nitrogen for 20 minfollowed by addition of palladium (II) acetate (0.145 g, 0.646 mmol).The resulting mixture was heated at 65° C. for 16 h. The reactionmixture was cooled to rt and filtered through CELITE®, the filtrate wasconcentrated and the residue was purified on a silica gel column to givethe title compound. LC/MS: (M+1)⁺: 406.21.

Step H:(1R,3′s,5S)-3-methyl-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-3,9-diazaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidin-]-2′-one:To a solution of the compound of Step G (2.63 g, 6.49 mmol) indichloromethane (5 mL) was added trifluoroacetic acid (10 mL, 130 mmol)and the resulting solution was stirred at rt for 1 h. After removing thevolatiles the residue was basified on ion exchange column washed withmethanol followed by 1 N ammonia/methanol to give the title compound.LC/MS: (M+1)⁺: 306.09.

Intermediate 35

6-Hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: Ethyl 1-benzyl-4-(cyanomethyl)-3-oxopiperidine-4-carboxylate: Toa flask charged with ethyl 1-benzyl-3-oxopiperidine-4-carboxylate (1.0g, 3.8 mmol) and a stir bar was added K₂CO₃ (1.06 g, 7.6 mmol),bromoacetonitrile (0.92 g, 7.6 mmo0, and acetone (15 mL). The reactionwas allowed to stir at RT for 2 hours. LC showed slow reaction. It wasthen heated to 45° C. for 3 hours. LC showed complete reaction at thatpoint. The reaction was quenched with NH₄Cl, extracted with EtOAc, driedover Na₂SO₄, filtered and concentrated. The crude product was purifiedby MPLC to furnish the title compound. LCMS: m/z 301 (M+H)⁺.

Step B: 8-Benzyl-6-hydroxy-2,8-diazaspiro[4.5]decan-1-one: To a flaskcharged with ethyl1-benzyl-4-(cyanomethyl)-3-oxopiperidine-4-carboxylate (900 mg, 3.0mmol) and a stir bar was added platinum oxide (100 mg, 0.44 mmol), MeOH(20 mL) and acetic acid (20 mL). The mixture was allowed to stirvigorously under an atmosphere of hydrogen for 24 hours. LC indicatedcomplete reaction at that point. The catalyst was removed by filtrationthrough a pad of CELITE®, and the filtrate was concentrated underreduced pressure. The residue was dissolved in EtOH (100 mL), and K₂CO₃was added (2.1 g, 15 mmol). The mixture was heated to 90° C. for 4hours. The reaction was cooled, and DCM was added (200 mL) toprecipitate the solids. The solids were then removed by filtration, andthe crude reaction was adsorbed onto silica gel, and flushed out withDCM and 10% MeOH (mixed with 10% NH₄OH) to give the title compound.LCMS: m/z 261 (M+H)⁺.

Step C:8-Benzyl-6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a flask charged with8-benzyl-6-hydroxy-2,8-diazaspiro[4.5]decan-1-one (520 mg, 2.0 mmol) anda stir bar was added palladium acetate (22 mg, 0.10 mmol), K₂CO₃ (550mg, 4.00 mmol), Xantphos (120 mg, 0.20 mmol),4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (640 mg,2.6 mmol), and water (110 mg, 6.0 mmol). The mixture was heated to 60°C. for 2 hours. LC showed complete reaction at that point. The reactionwas diluted with EtOAc, washed with water, and the phases separated. Thecrude solution was dried over Na₂SO₄, filtered and concentrated to anoil. The oil was loaded onto a silica gel column, and purified by MPLCwith Hexane and EtOAc. Two spots were separated with the desiredmolecular weight in a ratio of about 1 to 7. The more polar spot was themajor product. LCMS: m/z 357 (M+H)⁺.

Step D:6-Hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneTo a solution of8-benzyl-6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(150 mg, 0.42 mmol) in MeOH (2 mL) was added palladium on carbon (45 mg,0.42 mmol) and a few drops of HOAc. The mixture was allowed to stirunder an atmosphere of hydrogen for 16 hours. LC indicated completereaction. The catalyst was filtered off, and the crude material was usedwithout further purification. LCMS: m/z 267 (M+H)⁺.

Intermediates 36A and 36B (Two Isomers)

6-Fluoro-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,Isomers A and B

Step A:8-benzyl-6-fluoro-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneIsomers A and B)

To a flask charged with DCM (5 mL) and a stir bar was added DAST (0.092mL, 0.69 mmol) at −78° C., which was followed by addition of8-benzyl-6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-35, Step C) (165 mg, 0.46 mmol) in DCM. The mixture was stirred at−78° C. for 15 minutes, and then allowed to warm up to RT slowly. Thereaction was quenched with aq NaHCO₃ and after 3 hours at RT it wasextracted with DCM, dried over sodium sulfate, and purified by MPLC withhexane and EtOAc. Two spots were collected with the desired moleculeweight in the ratio of 1:4. The less polar compound, which is the minorisomer, was designated as Isomer A, and the more polar major isomer wasdesignated as Isomer B. LCMS: m/z 359 (M+H)⁺.

Step B-1:6-Fluoro-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneIsomer B, I-36B:

To a solution of Isomer B from Step A (100 mg, 0.28 mmol) in DCE (2 mL)was added ACE-Cl (0.15 mL, 1.4 mmol). The mixture was heated to 80° C.for 3 hours. The solvent was then removed, and the residue was pumpedunder high vacuum for 15 minutes. The residue was then dissolved in MeOH(5 mL) and heated to reflux for 30 minutes. LC showed formation of thedesired product. The reaction was concentrated, and the crude productwas purified by MPLC with a DCM and MeOH system to obtain Isomer B ofthe title compound (which is I-36B). LCMS: m/z 269 (M+H)⁺.

Step B-2:6-Fluoro-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Isomer A, I-36A): The title intermediate (which is I-36A) was preparedfollowing the same method as described in Step B-1, but starting fromIsomer A from Step A). LCMS: m/z 269 (M+H)⁺.

Intermediates 37A and 37B

4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,Isomer A and Isomer B

Step A: 1-tert-butyl 4-methyl4-(2-((tert-butoxycarbonyl)amino)-1-hydroxyethyl)piperidine-1,4-dicarboxylate:To a solution of LDA (prepared by adding n-butyllithium (20.0 mL, 49.3mmol) to diisopropylamine (5.16 mg, 51.0 mmol) in THF (40 mL) at 0° C.,stirred for 30 min) was added 1-tert-butyl 4-methylpiperidine-1,4-dicarboxylate (4.00 g, 16.4 mmol) in TMEDA (15 mL, 99mmol) drop-wise via syringe pump at −78° C. for 10 min. The mixture wasstirred at the same temperature for 30 min, then tert-butyl(2-oxoethyl)carbamate (8.11 g, 51.0 mmol) in THF (20 mL) was addedslowly by syringe pump for 15 min. The mixture was stirred at −78° C.for 30 min, quenched with saturated NH₄Cl at −78° C., warmed up to rtand diluted with EtOAc (200 mL). The organic layer was separated, andthe aqueous layer was extracted with EtOAc (100 mL). The combinedorganic layers were washed with brine, dried (MgSO₄), and concentrated.The residue was purified by column chromatography (80 g, silical gel,MeOH/DCM, gradient 0-10%, monitor at 210 nm) to afford title compound.LC/MS: [(M+1)]⁺=403

Step B: tert-Butyl4-hydroxy-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: To a solutionof 1-tert-butyl 4-methyl4-(2-((tert-butoxycarbonyl)amino)-1-hydroxyethyl)piperidine-1,4-dicarboxylate(4000 mg, 9.94 mmol) in DCM (100 mL) was added TFA (23 mL, 298 mmol) at0° C. and the resulting solution was stirred for 2 h. After removing thevolatiles, it was put on high vacuum briefly to remove excess TFA, andthe residue was dissolved in MeOH (100 mL), and potassium carbonate(13.7 g, 99 mmol) was added. The reaction mixture was heated at 60° C.for 2 h. After cooling to room temperature, aqueous NaHCO₃ (50 mL) wasadded to the reaction mixture. (BOC)₂O (6.51 g, 29.8 mmol) was added,and the reaction mixture was stirred overnight. The reaction mixture wasextracted with DCM, dried with MgSO₄, and concentrated to give the crudeproduct, which was purified by column chromatography (0-20% MeOH/DCM,monitor at 210 nm) to afford the title compound. LC/MS: [(M+1)]⁺=271

Step C: tert-Butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate,Isomer A and Isomer B

To a round bottom flask was charged tert-butyl4-hydroxy-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (400 mg, 1.48mmol), 4-methyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate(546 mg, 2.22 mmol), Pd₂(dba)₃ (33.9 mg, 0.037 mmol), Xantphos (64.2 mg,0.111 mmol), and cesium carbonate (964 mg, 2.96 mmol). The flask wasequipped with a condenser, vacuumed and back filled with N₂ and filledwith dioxane (6 mL). The reaction mixture was heated at 90° C.overnight, and filtered through CELITE®. The filtrate was evaporated togive the crude product, which was purified by column chromatography(0-10% MeOH/DCM) to give the title compound as a racemate. LCMS:[(M+1)]⁺=367. The racemic mixture was separated by SFC-HPLC, using thefollowing conditions: chiralcel OJ, 21×250 mm, 10% MeOH+0.2 DEA, 50mL/min to afford Isomer A (faster eluting enantiomer) LC/MS:[(M+1)]⁺=367, and Isomer B (slower eluting enantiomer) LC/MS:[(M+1)]⁺=367.

Step D:4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,Isomer A and Isomer B: The title compounds were prepared from Isomers Aand B of tert-Butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate,respectively, using TFA in a similar fashion as described previously for1-19. Isomer A: LC/MS: [(M+1)]⁺=267; Isomer B: LC/MS: [(M+1)]⁺=267.

Intermediate 38

2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-1,4-dione

Step A: tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2,8-diazaspiro[4.5]decane-8-carboxylate:To tert-butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(I-37, Step C) (200 mg, 0.546 mmol) in DCM (2.8 mL) was added sodiumbicarbonate (68.8 mg, 0.819 mmol) and Dess-Martin periodinane (347 mg,0.819 mmol). The reaction mixture was vigorously stirred for 1.5 h, thenquenched with 10% Na₂S₂O₃, NaHCO₃, and stirred for 20 min. The aqueouslayer was extracted with DCM, and the organic layers were washed withbrine, dried, and concentrated to give the title compound. LC/MS:[(M+1)]⁺=365;

Step B:2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-1,4-dione:The title compound was prepared from tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2,8-diazaspiro[4.5]decane-8-carboxylatein a similar fashion as described in I-19. LC/MS: [(M+1)]⁺=265

Intermediates 39A and 39B

4-Methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,Isomer A and Isomer B

Step A: tert-Butyl4-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(Enantiomer A and Enantiomer B): To a solution of tert-butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(100 mg, 0.273 mmol) in acetonitrile (1 mL) was added iodomethane (171μL, 2.73 mmol) and silver oxide (69.6 mg, 0.300 mmol). The vial wassealed, wrapped with aluminum foil, and stirred at 58° C. for 15 h. Thereaction mixture was filtered through CELITE®, concentrated to give thecrude product, which was purified by column chromatography (0-10%MeOH/DCM) to afford the title compound as a mixture of enantiomers.LC/MS: [(M+1)]⁺=381. The racemic mixture was separated by SFC-HPLC,using the following conditions: chiralcel AD-H, 2×25 cm, 15% MeOH, 60mL/min to afford faster eluting Enantiomer A: LC/MS: [(M+1)]⁺=381; andslower eluting Enantiomer B: LC/MS: [(M+1)]⁺=381

Step B:4-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,Isomer A and Isomer B: The individual isomers of the title compound wereprepared from each of the single Enantiomers from the previous step in asimilar fashion as described for 1-19, Step B, using TFA. Isomer A(derived from Enantiomer A, Step A): LCMS: [(M+1)]⁺=281. Isomer B(derived from Enantiomer B, Step A): LC/MS: [(M+1)]⁺=281.

Intermediate 40

2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one

Step A: tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate:To a solution of tert-butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(300 mg, 0.819 mmol) in DCM (8.2 mL) at 0° C. was added DBU (370 μA,2.46 mmol), and XtalFluor-E® (562 mg, 2.46 mmol). The mixture wasstirred overnight while warming up to rt, and quenched with aqueousNaHCO₃. The organic layer was separated and the aqueous layer wasextracted with DCM (30 mL). The combined organic layers were dried(MgSO₄) and purified by column chromatography (0-100% EtOAc/hex) to givethe title compound. LC/MS: [(M+1)]⁺=349

Step B:2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one:The title compound was prepared from tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylateusing TFA in an analogous fashion to that described for making 1-19,Step B. LC/MS: [(M+1)]⁺=249.

Intermediate 41

2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one

Step A: tert-Butyl4-hydroxy-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:To a round bottom flask was charged tert-butyl4-hydroxy-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (300 mg, 1.11mmol), 4-bromofuran-2(5H)-one (271 mg, 1.66 mmol), Pd(OAc)₂ (24.9 mg,0.111 mmol), Xantphos (96 mg, 0.166 mmol), and K₂CO₃ (307 mg, 2.22mmol). The flask was sealed, vacuumed and back filled with N₂ and filledwith dioxane (4.5 mL) and H₂O (60.0 μL, 3.33 mmol). The reaction mixturewas heated at 90° C. overnight, then filtered through CELITE®, andevaporated to give the crude product, which was purified by columnchromatography (0-10% MeOH/DCM) to give the title compound. LC/MS:[(M+1)]⁺=353

Step B: tert-Butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate:To a solution of tert-butyl4-hydroxy-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(210 mg, 0.596 mmol) in DCM (6 mL) at 0° C. was added DBU (269 μA, 1.79mmol), and XtalFluor-E® (409 mg, 1.79 mmol). The reaction mixture wasstirred overnight while warming up to rt, then quenched with aqueousNaHCO₃. The organic layer was separated and the aqueous layer wasextracted with DCM (30 mL). The combined organic layers were dried(MgSO₄) and purified by column chromatography (0-100% EtOAc/hex) to givethe title compound. LCMS: [(M+1)]⁺=335;

Step C:2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one: Thetitle compound was prepared from tert-Butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylateusing TFA in an analogous fashion to that described for 1-19, Step B.LC/MS: [(M+1)]⁺=235

Intermediate 42

3-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared in two steps in an analogous fashion tothat described for3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-22), except starting from4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (I-9).LC-MS (IE, m/z): 265 (M+1)⁺.

Intermediate 43

3-ethyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: 1-tert-butyl 4-ethyl4-(2-bromoallyl)piperidine-1,4-dicarboxylate: Lithium diisopropylamide(29.1 mL, 58.3 mmol) was added dropwise at −78° C. To a solution of1-tert-butyl 4-ethyl piperidine-1,4-dicarboxylate (9.56 mL, 38.9 mmol)in THF (200 mL), and stirred at this temperature for 50 min.2,3-Dibromoprop-1-ene (5.47 mL, 56.0 mmol) in THF (10 mL) was added tothe reaction mixture slowly and the resulting mixture was stirred for1.5 hr at −78° C. The reaction mixture was queched with NH₄Cl solution(15 mL) and was allowed to warm to room temperature and the aqueouslayer was extracted with EtOAc (30 mL×3). The combined organics werewashed with brine (30 mL), dried over MgSO₄ and concentrated to get thecrude product which was purified by silica gel column chromatography(RediSep 220 g Gold column) using (0-30) % EtOAc/Hexanes as mobile phaseto give the title compound.

Step B: 1-tert-butyl 4-ethyl4-(2-methylenebutyl)piperidine-1,4-dicarboxylate: To a solution of1-tert-butyl 4-ethyl 4-(2-bromoallyl)piperidine-1,4-dicarboxylate (5.0g, 13.3 mmol) in THF (80 mL) in a sealed tube was added BINAP (3.31 g,5.32 mmol), diethylzinc (15.95 mL, 15.95 mmol) and Pd(OAc)₂ (0.597 g,2.66 mmol) and the resulting mixture was degassed and heated for 16hours at 100° C. The reaction mixture was evaporated to remove solventunder reduced pressure and the crude product was purified by silica gelcolumn chromatography (RediSep 220 g Gold column) using (0-30) %EtOAc/Hexanes as mobile phase and the title compound was isolated.

Step C: 1-tert-butyl 4-ethyl 4-(2-oxobutyl)piperidine-1,4-dicarboxylate:Potassium tetrahydroxydioxidoosmium (0.041 g, 0.111 mmol) was added to asolution of 1-tert-butyl 4-ethyl4-(2-methylenebutyl)piperidine-1,4-dicarboxylate (1.0 g, 3.07 mmol) inacetone (20 mL) and water (20 mL) and stirred for 10 min. Solid sodiumperiodate (2.62 g, 12.26 mmol) was added in four portions during 1 hourand the reaction temperature was maintained below 40° C. using anice-bath. The resulting mixture was stirred for 1 hour at roomtemperature. At this point LCMS showed incomplete reaction. Another0.036 eq. of potassium tetrahydroxydioxidoosmium (0.041 g, 0.111 mmol)was added and the mixture was then stirred at rt for 2 hours. LCMS after2 hours showed completion of the reaction. The suspension was filteredand filtrate was concentrated to remove acetone, and the aqueous layerwas extracted with DCM (15 mL×3). The combined organic layers werewashed with 10% Na₂S₂O₃ solution (20 ml×2), dried over anhydrous Na₂SO₄,filtered, then concentrated to get the crude product which was purifiedby silica gel column chromatography (80 g RediSep Gold column) using(0-35) % EtOAc/Hexanes as mobile phase and the title compound wasisolated.

Step D: tert-butyl3-ethyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: To a stirredsolution of 1-tert-butyl 4-ethyl4-(2-oxobutyl)piperidine-1,4-dicarboxylate (0.78 g, 2.38 mmol) inethanol (24 mL) in a sealed tube was added ammonium acetate (2.39 g,31.0 mmol), sodium cyanoborohydride (0.422 g, 6.72 mmol) and magnesiumsulfate (1.577 g, 13.10 mmol) and the resulting mixture was heated for16 hours at 80° C. The reaction mixture was filtered over CELITE® toremove MgSO₄ and the filtrate was concentrated. The residue wasre-dissolved in DCM (20 mL) and washed with saturated NaHCO₃ (10 ml),water (10 mL) and brine (10 mL). The organic layer was dried overanhydrous MgSO₄ filtered, concentrated, then purified by silica gelcolumn chromatography (40 g RediSep Gold column) using (0-10) %MeOH/EtOAc to give the title compound.

Steps E and F:3-ethyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:The title compound was prepared in two steps from tert-butyl3-ethyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate in an analogousfashion as described for3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-22).

Intermediate 44

3-cyclopropyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: 1-tert-butyl 4-ethyl4-(2-cyclopropylallyl)piperidine-1,4-dicarboxylate: 1-tert-butyl 4-ethyl4-(2-bromoallyl)piperidine-1,4-dicarboxylate (1.0 g, 2.66 mmol),potassium cyclopropyltrifluoroborate (0.413 g, 2.79 mmol), cesiumcarbonate (2.60 g, 7.97 mmol) and[1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.058 g,0.080 mmol) were taken up in toluene (14 mL) and water (1.39 mL) in amicrowave vial, degassed and heated at 80° C. overnight. The reactionmixture was cooled and LC/MS was taken which showed almost completion ofreaction. The reaction mixture was diluted with EtOAc and water. Aqueouslayer was extracted with EtOAc (2×), the combined organic layers weredried over anhydrous MgSO₄, filtered, concentrated, and purified bysilica gel column chromatography (RediSep Gold, 80 g) using (0-30) %EtOAc/Hexanes as mobile phase to afford the title compound.

3-cyclopropyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneThe title compound was prepared from 1-tert-butyl 4-ethyl4-(2-cyclopropylallyl)piperidine-1,4-dicarboxylate in four steps in ananalogous fashion as described for3-ethyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-43).

Intermediate 45

3-cyclopropyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared in an analogous fashion to 1-44, butusing 4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate.

Intermediate 46

2-(4-(methoxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: tert-butyl2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-butyl1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(I-16, Step A) (2.73 g, 8.12 mmol) was dissolved in DCM (70 mL) and wastreated with N-bromosuccinimide (1.73 g, 9.74 mmol) at 25° C. and theresulting mixture was stirred overnight at room temperature. The nextday, the reaction mixture was diluted with DCM and was washed with waterand brine then dried over Na₂SO₄. Removing solvent gave crude productthat was purified by silica gel column chromatography (80 g RediSep GoldColumn) using (25-80) % EtOAc/Hexanes as mobile phase to afford thetitle compound.

Step B: tert-butyl1-oxo-2-(5-oxo-4-vinyl-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-butyl2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(2.2 g, 5.30 mmol), potassium trifluoro(vinyl)borate (1.06 g, 7.95mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II)(0.345 g, 0.530 mmol) and potassium phosphate tribasic (10.60 mL, 10.60mmol) were taken up in THF (44.1 mL) in a sealed tube, de-gassed and theresulting mixture was heated overnight at 70° C. The reaction mixturewas cooled to room temperature and then was diluted with EtOAc andwater. After separation of layers, the aqueous layer was extracted withEtOAc (2×). The combined organic layers were dried over anhydrous MgSO₄,filtered, concentrated and purified by silica gel column chromatographyusing (30-100) % EtOAc/hexanes as mobile phase to provide the titlecompound.

Step C: tert-butyl2-(4-formyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-butyl1-oxo-2-(5-oxo-4-vinyl-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate(1.6 g, 4.4 mmol) was dissolved in acetone (36 mL) and water (36 mL),then K₂OsO₄.2H₂O was added and the mixture was stirred for ˜5 min. Solidsodium periodate (3.77 g, 17.6 mmol) was added in 4 portions during 1hour and the reaction temperature was maintained below 40° C. using anice-bath. The resulting mixture was stirred for 1 hour at roomtemperature. LCMS after 2 hours showed complete consumption of startingmaterial. The suspension was filtered and the filtrate was concentratedto remove acetone. The aqueous layer was extracted with DCM (3×).Combined organic layers were washed with 10% Na₂S₂O₃ solution (2×),dried over anhydrous Na₂SO₄, filtered, concentrated to obtain the titlecompound, which was taken to the next step without further purification.

Step D: tert-butyl2-(4-(hydroxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-butyl2-(4-formyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(1.18 g, 3.24 mmol) was dissolved in THF (13 mL) and MeOH (13 mL) andthe mixture was cooled to −78° C. and stirred for 15 min. Sodiumborohydride (0.147 g, 3.89 mmol) was added in two equal portions and theresulting mixture was stirred for ˜15 min. at −78° C. LC-MS after 15minutes stirring at −78° C. showed complete consumption of startingmaterial. The reaction mixture was diluted with ethyl acetate andquenched with aqueous ammonium chloride solution at −78° C. The aqueouslayer was extracted with EtOAc (2×), combined organic layers were washedwith water, brine, then dried (MgSO₄) and filtered, and the solvent wasevaporated under reduced pressure to obtain the product, which was takento the next step without purification.

Step E: tert-butyl2-(4-(methoxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:tert-butyl2-(4-(hydroxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(0.42 g, 1.15 mmol), silver oxide (0.292 g, 1.26 mmol) and methyl iodide(0.358 mL, 5.73 mmol) were taken up in DCM (5 mL) and stirred over nightat room temperature under nitrogen. Additional silver oxide (0.292 g,1.26 mmol) and methyl iodide (0.358 mL, 5.73 mmol) were added to themixture with DCE (8 mL) and the resulting mixture was heated at 54° C.overnight. The reaction mixture was filtered through CELITE® to removesilver oxide, concentrated, and purified by silica gel columnchromatography (40 g RediSep Gold column) using (20-80) % EtOAc/DCM asmobile phase to afford the title compound.

Step F:2-(4-(methoxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:The title compound was prepared from tert-butyl2-(4-(methoxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylatein an analogous fashion as described for3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-22, last step).

Intermediate 47

3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one

Step A: 1-tert-Butyl 4-methyl4-(2-((tert-butoxycarbonyl)amino)-1-hydroxypropyl)piperidine-1,4-dicarboxylate:To a solution of LDA (prepared by adding n-BuLi (27.7 mL, 55.5 mmol) todiisopropylamine (8.04 mL, 57.3 mmol) in THF (40 mL) at 0° C., stir for30 min) was added 1-tert-butyl 4-methyl piperidine-1,4-dicarboxylate(4500 mg, 18.5 mmol) in TMEDA (16.6 mL, 111 mmol) dropwise via syringepump at −78° C. for 20 min. The mixture was stirred at the sametemperature for 30 min, and (S)-tert-butyl (1-oxopropan-2-yl)carbamate(9931 mg, 57.3 mmol) in THF (20 mL) was added slowly by syringe pump for20 min. The mixture was stirred at −78° C. for 30 min, and quenched withsaturated NH₄Cl at −78° C., warmed up to rt and diluted with EtOAc (200mL). The organic layer was separated, and the aqueous layer wasextracted with EtOAc (100 mL). The combined organic layers were washedwith brine, dried (MgSO₄), and concentrated. The residue was purified bycolumn chromatography (MeOH/DCM, gradient 0-10%) to afford the titlecompound. LC/MS: [(M+1)]⁺=417

Step B: tert-Butyl4-hydroxy-3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate: To asolution of 1-tert-butyl 4-methyl4-(2-((tert-butoxycarbonyl)amino)-1-hydroxypropyl)piperidine-1,4-dicarboxylate(8000 mg, 19.2 mmol) in DCM (190 mL) was added TFA (44.4 mL, 576 mmol)at 0° C. and the resulting solution was stirred for 2 h. After removingthe volatiles, high vacuum was applied briefly to remove excess TFA, andthe residue was dissolved in MeOH (190 mL), and K₂CO₃ (26.5 g, 192 mmol)was added. The reaction mixture was heated at 60° C. for 2 h. Aftercooling to room temperature, saturated NaHCO₃ solution (60 mL) wasadded, followed by (BOC)₂O (12.6 g, 57.6 mmol). The reaction mixture wasstirred overnight, and extracted with DCM. The organic layer was driedwith MgSO₄, and concentrated to give the crude product, which waspurified by column chromatography (0-20% MeOH/DCM, monitored at 210 nM)to give the title compound. LCMS: [(M+1)]⁺=285

Step C: tert-Butyl4-hydroxy-3-methyl-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:To a round bottom flask was charged tert-butyl4-hydroxy-3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (1000mg, 3.52 mmol), 4-bromofuran-2(514)-one (860 mg, 5.28 mmol), Pd(OAc)₂(79 mg, 0.352 mmol), Xantphos (305 mg, 0.528 mmol), and K₂CO₃ (972 mg,7.03 mmol). The flask was sealed, vacuumed and back filled with N₂ andfilled with dioxane (14 mL) and water (190 μL, 10.6 mmol). The reactionmixture was heated at 90° C. overnight, and filtered through CELITE®.The filtrate was evaporated to give the crude product, which waspurified by column chromatography (0-10% MeOH/DCM, came out at 6%MeOH/DCM, followed by another column with 0-100% EtOAc/hex) to give thetitle compound. LCMS: [(M+1)]⁺=367

Step D: tert-butyl4-iodo-3-methyl-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate:To a solution of the compound of step C (370 mg, 1.01 mmol) in toluene(20 mL) at rt was added PPh₃ (397 mg, 1.515 mmol), imidazole (137 mg,2.02 mmol), and I₂ (384 mg, 1.515 mmol). The mixture was stirred for 10h at 100° C., and quenched with NaHCO₃ aqueous solution. The organiclayer was diluted with DCM, separated, and the aqueous layer wasextracted with DCM. The combined organic layers were dried (MgSO₄) andpurified by column chromatography (0-100% EtOAc/hex) to give the titlecompound. LC/MS: [(M+1−56)]⁺=421

Step E:4-iodo-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:The compound of Step D (100 mg, 0.210 mmol) in DCM (1.1 mL) was treatedwith TFA (485 μL, 6.30 mmol) at 0° C. to remove the Boc group whichprovided the TFA salt after solvent evaporation. Then a 2 g Bond ElutSCX column was first rinsed with MeOH, load sample with MeOH, washedwith MeOH dropwise to remove TFA, and finally rinsed with 2N NH₃MeOH togive the title compound as a free base. LC/MS: [(M+1)]⁺=377

Step F:3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one:To a solution of the compound of Step E (180 mg, 0.478 mmol) in THF (4.8mL) at rt was added10-ethyl-2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine(polymer-bound, 1.15 mmol/g, 2.5 g resin). The reaction mixture washeated at 60° C. for 5 h on a shaker, then the resin was filtered offwith a MeOH rinse, and the resulting mixture was evaporated to give thetitle compound. LCMS: [(M+1)]⁺=249

Intermediate 48

4-Methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one

Step A: tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2,8-diazaspiro[4.5]decane-8-carboxylate:To tert-butyl4-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(see example I-37A and I-37B, Step C, racemate prior to chiral HPLCseparation)(200 mg, 0.546 mmol) in DCM (2.8 mL) was added sodiumbicarbonate (68.8 mg, 0.819 mmol) and Dess-Martin periodinane (347 mg,0.819 mmol). The reaction mixture was vigorously stirred for 1.5 h, thenquenched with 10% Na₂S₂O₃ and NaHCO₃ aqueous solutions, and stirred for20 min. The aqueous layer was extracted with DCM, and the organic layerswere washed with brine, dried, and concentrated to give tert-butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2,8-diazaspiro[4.5]decane-8-carboxylate.LCMS: [(M+1)]⁺=365

Step B: tert-butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-4-(((trifluoromethyl)sulfonyl)oxy)-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate:To a flask containing tert-butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2,8-diazaspiro[4.5]decane-8-carboxylate(200 mg, 0.549 mmol) in THF (3 mL) was added NaHMDS (1.10 mL, 1 M inTHF, 1.10 mmol) dropwise over 5 min at −78° C. The solution was stirredfor 2 h, then N-phenylbis(trifluoromethanesulfonimide) (314 mg, 0.878mmol) in THF (2 mL) was added dropwise over 5 min. The reaction mixturewas stirred for 2 h at −78° C., then warmed to room temperature andstirred overnight. The reaction solution was quenched by the addition ofsaturated aq. NH₄Cl and extracted with EtOAc. The combined organiclayers were dried (MgSO₄) and concentrated. The crude material waspurified by column chromatography (0-10% MeOH/DCM) to afford the titlecompound. LC/MS: [(M+1)]⁺=497

Step C: tert-butyl4-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate:tert-Butyl2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-4-(((trifluoromethyl)sulfonyl)oxy)-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate(180 mg, 0.363 mmol) was dissolved in THF (3.6 mL), and Pd(Ph₃P)₄ (209mg, 0.181 mmol) was added, followed by trimethylaluminum (3.6 mL, 7.25mmol) at 0° C. This reaction was stirred at rt for 2 h before it wasquenched with saturated aqueous NaHCO₃ solution at 0° C. (highlyexothermic). This mixture was diluted with EtOAc, dried over Mg₂SO₄ andconcentrated under reduced pressure. The crude material was purified bycolumn chromatography (0-10% MeOH/DCM) to afford the title compound.LC/MS: [(M+1)]⁺=363

Step D:4-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-onetert-Butyl4-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-3-ene-8-carboxylate(130 mg, 0.359 mmol) in DCM (1.8 mL) was treated with TFA (0.8 mL, 10.7mmol) at 0° C. to remove the Boc group which provided the TFA salt. TheTFA salt was loaded onto a 2 g Bond Elut SCX ion-exchange column withMeOH, then further washed with MeOH dropwise to remove TFA, and finallyrinsed with 2 N NH₃MeOH to give the title compound as a free amine.LCMS: [(M+1)]⁺=263

Intermediate 49

4-ethyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 5-bromo-4-ethyl-2-benzofuran-1(3H)-one: A mixture of5-bromo-4-vinyl-2-benzofuran-1(3H)-one (2.0 g, 8.37 mmol) and PdC (400mg) in 50 mL of MeOH was stirred at rt. under H₂ (1 atm) overnight, andthen filtered. The filtrate was concentrated. The resulting oil waspurified by column chromatography to give5-bromo-4-ethyl-2-benzofuran-1(3H)-one.

Step B: 4-ethyl-5-vinyl-2-benzofuran-1(3H)-one: A mixture of5-bromo-4-ethyl-2-benzofuran-1(3H)-one (1.81 g, 7.51 mmol), potassiumvinyltrifluoroborate (1.21 g, 9.01 mmol) and Pd(dppf)Cl₂ (200 mg) in 20mL of TEA and 20 mL of EtOH was heated to reflux under N₂ overnight andthen concentrated. The resulting material was purified by columnchromatography to give 4-ethyl-5-vinyl-2-benzofuran-1(3H)-one.

Step C: 4-ethyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one: To a solution of4-ethyl-5-vinyl-2-benzofuran-1(3H)-one (1.1 g, 5.85 mmol) in 50 mL ofDCM was slowly added mCPBA (3.60 g, 85% purity, 17.6 mmol) in 50 mL ofDCM at 0° C. The mixture was warmed to room temperature, and thenstirred for 3 days. The mixture was washed with aqueous Na₂SO₃ until KIpaper didn't change color. The organic layers were combined, washed withbrine and concentrated. The residue was purified by columnchromatography to give 4-ethyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one.¹H-NMR (400 MHz, CDCl₃) δ ppm 7.75 (d, J=8.6 Hz, 1H), 7.41 (d, J=7.8 Hz,1H), 5.30 (s, 2H), 4.11-4.13 (m, 1H), 3.23-3.25 (m, 1H), 2.75-2.82 (m,2H), 2.70-2.72 (m, 1H), 1.27 (t, J=7.4 Hz, 3H).

Intermediate 50

4-cyclopropyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 5-bromo-4-iodo-2-benzofuran-1(3H)-one: To a cooled (0° C.)solution of 5-bromo-2-benzofuran-1(3H)-one (50 g, 0.235 mol) intrifluoromethanesulfonic acid (400 mL) was added N-iodosuccinimide (55.5g, 0.247 mol). The resulting mixture was stirred at room temperatureovernight, then poured slowly into ice water (2 L), filtered and thefiltrate extracted with EtOAc. The combined organic layers were washedwith water and brine, dried and concentrated to give5-bromo-4-iodo-2-benzofuran-1(3H)-one.

Step B: 5-bromo-4-vinyl-2-benzofuran-1(3H)-one: A mixture of5-bromo-4-iodo-2-benzofuran-1(3H)-one (1 g, 2.95 mmol), potassiumvinyltrifluoroborate (474 mg, 3.54 mmol) and Pd(dppf)Cl₂ (200 mg) in 20mL of TEA and 20 mL of EtOH was heated to reflux under N₂ for 2 hours.TLC showed complete reaction. Most of the solvent was removed, and theresidue was dissolved in EtOAc (100 mL). The solution was washed with0.1 N HCl, sodium bicarbonate, and brine, dried over sodium sulfate,filtered and concentrated to provide5-bromo-4-vinyl-2-benzofuran-1(3H)-one.

Step C: 5-bromo-4-cyclopropyl-2-benzofuran-1(3H)-one: To a cooled (0°C.) mixture of 5-bromo-4-vinyl-2-benzofuran-1(3H)-one (2.2 g, 9.21 mol)and Pd(OAc)₂ (100 mg) in EtOAc (50 mL) was added a solution of CH₂N₂ inether (100 mL) slowly. The resulting mixture was stirred at roomtemperature overnight, then quenched with acetic acid, filtered and thefiltrate washed with water and brine, dried and concentrated to providetitle compound.

Step D: 4-cyclopropyl-5-vinyl-2-benzofuran-1(3H)-one: A mixture of5-bromo-4-cyclopropyl-2-benzofuran-1(3H)-one (760 mg, 3.004 mmol),potassium vinyltrifluoroborate (805 mg, 6.01 mmol) and Pd(dppf)Cl₂ (100mg) in 20 mL of TEA and 20 mL of EtOH was heated to reflux under N₂ for8 hours. After TLC showed complete reaction, then most of the solventwas removed and the residue was dissolved in EtOAc (100 mL). Thesolution was washed with 0.1 N HCl, sodium bicarbonate, and brine, driedover sodium sulfate, filtered and concentrated. The resulting oil waspurified by column chromatography to give the title compound.

Step E: 4-cyclopropyl-5-oxiran-2-yl-2-benzofuran-1(3H)-one: To asolution of 4-cyclopropyl-5-vinyl-2-benzofuran-1(3H)-one (440 mg, 2.2mmol) in 50 mL of DCM was slowly added mCPBA (1.14 g, 6.6 mmol) in 50 mLof DCM at 0° C. After warming to room temperature, the mixture wasstirred for 12 hours. The mixture was washed with aqueous Na₂SO₃ untilKI paper didn't change color. The organic layers were combined, washedwith brine and then concentrated. The residue was purified via prep-TLCto give the title compound. ¹H-NMR (400 MHz, CDCl₃) δ ppm 7.77 (d, J=8.6Hz, 1H), 7.39 (d, J=7.8 Hz, 1H), 5.39 (s, 2H), 4.43-4.45 (m, 1H),3.26-3.28 (m, 1H), 2.68-2.70 (m, 1H), 1.94-2.01 (m, 1H), 1.08-1.12 (m,2H), 0.65-0.75 (m, 2H).

Intermediate 51

4-chloro-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 2-chloro-3-(hydroxymethyl)phenol: To a solution of2-chloro-3-hydroxybenzaldehyde (8.10 g, 51.7 mmol) in MeOH was addedNaBH₄ (1.96 g, 51.7 mmol) at 0° C. The reaction was allowed to stir for30 minutes. The reaction was then diluted with EtOAc (400 mL), washedwith water and brine, dried over sodium sulfate, and concentrated. Thecrude product was used in Step B without further purification.

Step B: 4-bromo-2-chloro-3-(hydroxymethyl)phenol: To a flask chargedwith 2-chloro-3-(hydroxymethyl)phenol and a stir bar was added NBS (10.8g, 60.5 mmol) and TFA (50 mL). The reaction was allowed to stir for 16hours at RT, then the solvent was removed under vacuum. The residue wasre-dissolved in EtOAc, washed with water, and purified by silica gelflash chromatography. A pair of regio-isomers was collected from theseparation. The less polar spot was the desired4-bromo-2-chloro-3-(hydroxymethyl)phenol according to NMR analysis.

Step C: 4-chloro-5-hydroxy-2-benzofuran-1(3H)-one: To a flask chargedwith 4-bromo-2-chloro-3-(hydroxymethyl)phenol (2.44 g, 10.3 mmol) and astir bar, was added CuCN (2.76 g, 30.8 mmol) and DMF (25 mL). The flaskwas fitted with a condenser and purged three times with Nitrogen. hesolution was then heated to 145° C. for 2 hours. At that point, water(0.555 mL, 30.8 mmol) was added to the reaction via a syringe, and thereaction was kept at 100° C. for another 24 hours. The reaction wascooled to RT, diluted with DCM (100 mL), and filtered through a pad ofCELITE® to remove the solids. The filtrate was washed with saturatedNH₄OAc, dried over sodium sulfate, concentrated and purified by silicagel flash chromatography to afford title compound.

Step D: 4-chloro-5-ethenyl-2-benzofuran-1(3H)-one: To a cold solution of4-chloro-5-hydroxy-2-benzofuran-1(3H)-one (1.39 g, 7.53 mmol) in DCM (25mL) was added Hunig's Base (3.29 mL, 18.8 mmol) andtrifluoromethanesulfonic anhydride (2.54 mL, 15.1 mmol). The mixture wasallowed to stir for 16 hours. Analysis by TLC showed completeconsumption of all SM. The reaction was diluted with hexane and washedwith water. The solution was dried with sodium sulfate, concentrated,and purified by flash chromatography on a silica column. The solvent wasremoved under reduced pressure to give intermediate triflate. LC-MS(M+1=317). To the triflate was added a stir bar, potassiumvinyltrifluoroborate (1.33 g, 9.90 mmol), PdCl₂(dppf) (0.243 g, 0.332mmol), triethylamine (1.89 mL, 13.3 mmol), and iso-propanol (50 mL). Themixture was purged three times with nitrogen, and heated to 60° C. for 2hours. TLC showed complete reaction at that point. Most of the solventwas removed under vacuum. The crude residue was diluted with EtOAc (200mL), washed with brine, dried over sodium sulfate, adsorbed onto silicagel, and purified by flash chromatography to give the title compound.

Step E: 4-chloro-5-oxiran-2-yl-2-benzofuran-1(3H)-one: To a solution of4-chloro-5-ethenyl-2-benzofuran-1(3H)-one (1.1 g, 5.7 mmol) in DCM (40mL) was added mCPBA (1.9 g, 8.5 mmol). The solution was allowed to stirat RT for 16 hours. Analysis by TLC and LC showed formation of thedesired product. The reaction was diluted with DCM (200 mL), washed withaqueous Na₂S₂O₃ and Na₂CO₃, dried over sodium sulfate, concentrated, andpurified by silica gel flash chromatography to afford title compound.¹H-NMR (500 MHz, CDCl₃) δ ppm 7.86 (d, J=8.0 Hz, 1H), 7.48 (d, J=8.0 Hz,1H), 5.34 (s, 2H), 4.33 (m, 1H), 3.33 (m, 1H), 2.75 (m, 1H).

Intermediate 52

4-Fluoro-5-oxiran-2-yl-2-benzofuran-1(3H)-one

Step A: 5-Bromo-4-fluoro-2-benzofuran-1(3H)-one: A solution of n-BuLi(40 mL, 100 mmol) was added dropwise to a solution of diisopropylamine(10.6 g, 105 mmol) in 150 mL of THF at −70° C. The mixture was stirredat 0° C. for 15 minutes and then cooled to −70° C. again. A solution of4-bromo-3-fluorobenzoic acid (10 g, 45.7 mmol, in 50 mL of THF) wasadded dropwise. The resulting mixture was stirred at −70° C. for 1 hourthen CH₂O gas (generated by heating 5.1 g of Para formaldehyde to 200°C.) was bubbled into the mixture. The resulting mixture was stirred at−70° C. for 1 hour then allowed to warm to room temperature and stirredfor another 2 hours. HCl gas was bubbled into the suspension for 15minutes to give a solution. The mixture was diluted with 1 L of EtOAcand washed subsequently with water, saturated Na₂CO₃ and brine, driedover anhydrous Na₂SO₄ and concentrated to give5-bromo-4-fluoro-2-benzofuran-1(3H)-one. ¹H-NMR (400 MHz, CDCl₃) δ ppm7.72-7.75 (m, 1H), 7.58 (d, J=8.0 Hz, 1H), 5.36 (s, 2H).

Step B: 4-fluoro-5-vinyl-3H-isobenzofuran-1-one: A mixture of5-bromo-4-fluoro-2-benzofuran-1(3H)-one (5.0 g, 21.6 mmol), potassiumvinyltrifluoroborate (4.4 g, 32.5 mmol) and Pd(dppf)Cl₂ (500 mg) in 100mL of TEA and 100 mL of EtOH was heated to reflux under N₂ for 4 hrs andthen concentrated. The resulting oil was purified by columnchromatography to give 4-fluoro-5-vinyl-3H-isobenzofuran-1-one. ¹H-NMR(400 MHz, CDCl₃) δ ppm 7.67-7.68 (m, 2H), 6.90-6.97 (m, 1H), 6.00 (d,J=17.2 Hz, 1H), 5.60 (d, J=11.0 Hz, 1H), 5.35 (s, 2H).

Step C: 4-fluoro-5-oxiranyl-3H-isobenzofuran-1-one: To a solution of4-fluoro-5-vinyl-3H-isobenzofuran-1-one (4.0 g, 17.3 mmol) in 100 mL ofDCM was slowly added mCPBA (6.0 g, 85% purity, 34.6 mmol) in 50 mL ofDCM at 0° C. After warming to room temperature, the mixture was stirredovernight. The mixture was washed with aqueous Na₂SO₃ until KI paperdidn't change color. The organic layers were washed with brine and thenconcentrated. The residue was purified by column chromatography to give4-fluoro-5-oxiranyl-3H-isobenzofuran-1-one. ¹H-NMR (400 MHz, CDCl₃) δppm 7.71 (d, J=7.8 Hz, 1H), 7.37-7.40 (m, 1H), 5.37 (s, 2H), 4.21-4.22(m, 1H), 3.25-3.27 (m, 1H), 2.80-2.82 (m, 1H).

Intermediate 53

(1R,3′r,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidin]-2′-one

Step A: (1R,5S,E)-tert-butyl7-(1-cyano-2-methoxy-2-oxoethylidene)-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate:A solution of methyl 2-cyanoacetate (4.39 mL, 49.7 mmol),(1R,5S)-tert-butyl 7-oxo-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate(8 g, 33.2 mmol), ammonium acetate (3.83 g, 49.7 mmol), and acetic acid(7.59 ml, 133 mmol) in toluene (100 ml) was heated at 150° C. overnightand the water generated was separated by Dean-Stark trap. Afterevaporating the solvent the residue was dissolved in ethyl acetate (200mL) and the solution was washed with saturated sodium bicarbonate, driedover sodium sulfate, concentrated and the residue was purified on silicagel column using ethyl acetatehexane as eluting solvents to give thetitle compound. LCMS: (M+1-100)⁺: 223.01.

Step B: (1R,5S,7s)-tert-butyl7-(1-cyano-2-methoxy-2-oxoethyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate:To a suspension of (1R,5S,E)-tert-butyl7-(1-cyano-2-methoxy-2-oxoethylidene)-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate(10.82 g, 33.6 mmol) and copper(I) iodide (6.39 g, 33.6 mmol) intetrahydrofuran at 0° C. was added vinylmagnesium bromide (50.3 ml, 50.3mmol) slowly over 2 h. The resulting mixture was stirred from 0° C. tort for 2 h. The reaction was quenched by saturated ammonium chloride(300 mL), the mixture was extracted with ethyl acetate three times, thecombined organic phase was dried over sodium sulfate then concentrated,and the residue was purified on silica gel using ethyl acetatehexane aseluting solvents to give the title compound. LCMS: (M+23)⁺: 372.94.

Step C:2-((1R,5S,7s)-9-(tert-butoxycarbonyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonan-7-yl)-2-cyanoaceticacid: To a solution of (1R,5S,7s)-tert-butyl7-(1-cyano-2-methoxy-2-oxoethyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate(1.3 g, 3.7 mmol) in a mixture of tetrahydrofuran (10 ml), methanol (3ml) and water (3 ml) was added lithium hydroxide (18.55 ml, 18.55 mmol).The resulting solution was stirred at rt for 2 h. After removing thevolatiles the alkaline phase was acidified at 0° C. with 1N HCl to pH 4.The mixture was then extracted with 30% isopropanol/methylene chloride(3×100 mL), and the combined organic phase was dried over sodium sulfateand concentrated to give the title compound. LCMS: (M−100+1)⁺: 237.04.

Step D: (1R,5S,7r)-tert-butyl7-(cyanomethyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate: Asolution of2-((1R,5S,7s)-9-(tert-butoxycarbonyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonan-7-yl)-2-cyanoaceticacid (1.10 g, 3.27 mmol) in DMF (10 mL) was heated at 130° C. for 20min. After cooling to rt the reaction mixture was partitioned betweenethyl acetate (200 mL) and brine, the organic phase was washed withbrine three time, dried over sodium sulfate then concentrated, and theresidue was purified on silica gel column using ethyl acetate/hexane aseluting solvents to give the title compound. LCMS: (M−100+1)⁺: 193.08.

Step E: (1R,5S,7r)-tert-butyl7-(cyanomethyl)-7-formyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate:To a solution of (1R,5S,7r)-tert-butyl7-(cyanomethyl)-7-vinyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate(0.66 g, 2.257 mmol) in dioxane (10 ml) and water (3 ml) was addedsodium periodiate (1.931 g, 9.03 mmol) and osmium tetroxide (0.035 ml,0.113 mmol). The resulting mixture was stirred at rt overnight. Next,thiosulphate (2 g) was added and the mixture was stirred at rt for 0.5h. The reaction mixture was filtered and the filtrate was partitionedbetween methylene chloride and saturated sodium bicarbonate, and thealkaline phase was extracted with methylene chloride (3×100 mL). Thecombined organic phase was dried over sodium sulfate and concentrated togive the title compound. LCMS: (M−100+1)⁺: 195.09.

Step F:(1R,5S,7r)-9-(tert-butoxycarbonyl)-7-(cyanomethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7-carboxylicacid: To a solution of (1R,5S,7r)-tert-butyl7-(cyanomethyl)-7-formyl-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate(613 mg, 2.083 mmol) in tert-BuOH (10 ml) and water (5 ml) was addedsodium dihyrogen phosphate (750 mg, 6.25 mmol) and 2-methyl-2 butene(1.098 ml, 10.41 mmol). The solution was cooled to 0° C. and sodiumchlorite (565 mg, 6.25 mmol) was added by portions. The reactionsolution was stirred at 0° C. for 1 h. Additional sodium dihyrogenphosphate (750 mg, 6.25 mmol), 2-methyl-2 butene (1.098 ml, 10.41 mmol)and sodium chlorite (565 mg, 6.25 mmol) was added. The reaction mixturewas left to stir at 0° C. for 2 h before being quenched by addition of 1N HCl to pH 4. Next, the mixture was diluted in water (100 mL) and wasextracted with methylene chloride (3×100 mL) while maintaining pH 4 by 1N HCl. The combined organic phase was dried over sodium sulfate andconcentrated to give the title compound. LCMS: (M+23)⁺: 333.03.

Step G: (1R,5S,7r)-9-tert-butyl 7-methyl7-(cyanomethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7,9-dicarboxylate: To asolution of(1R,5S,7r)-9-(tert-butoxycarbonyl)-7-(cyanomethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7-carboxylicacid (646 mg, 2.082 mmol) in methanol (10 ml) was added TMS-diazomethane(5.20 ml, 10.41 mmol) dropwise until there was no bubble generation, andthen the reaction was quenched by addition of acetic acid (a few drops).The mixture was concentrated to give the title compound. LC/MS: (M+23)⁺:346.98.

Step H: (1R,5S,7r)-9-tert-butyl 7-methyl7-(2-aminoethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7,9-dicarboxylate: Amixture of (1R,5S,7r)-9-tert-butyl 7-methyl7-(cyanomethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7,9-dicarboxylate (0.58g, 1.788 mmol) and platinum(IV) oxide (0.082 g, 0.358 mmol) in methanol(10 ml) and acetic acid (10 ml) was hydrogenated at 45 Psi over theweekend. After filtration through CELITE® under nitrogen, the filtratewas concentrated to give the title compound. LC/MS: (M+1)⁺: 329.04.

Step I: (1R,3′r,5S)-tert-butyl2′-oxo-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate:A mixture of (1R,5S,7r)-9-tert-butyl 7-methyl7-(2-aminoethyl)-3-oxa-9-azabicyclo[3.3.1]nonane-7,9-dicarboxylate (0.59g, 1.797 mmol) and potassium carbonate (1.490 g, 10.78 mmol) in methanol(50 ml) was heated at reflux for 4 h. After evaporating the solvent, theresidue was partitioned between methylene chloride and water, and theaqueous phase was extracted with methylene five times. The combinedorganic phase was dried over sodium sulfate and concentrated to give thetitle compound. LCMS: (M+23)⁺: 319.03.

Step J: (1R,3′r,5S)-tert-butyl1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate:To a mixture of (1R,3′r,5S)-tert-butyl2′-oxo-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate(0.42 g, 1.417 mmol) and 4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (0.454 g, 1.842 mmol) in toluene (15 ml) wasadded potassium carbonate (0.588 g, 4.25 mmol), xantphos (0.328 g, 0.567mmol), and water (0.077 ml, 4.25 mmol). The mixture was flushed withnitrogen for 20 min before addition of palladium (II) acetate (0.064 g,0.283 mmol). The resulting mixture was heated at 70° C. overnight. Afterfiltration the residue was purified on silica gel column using ethylacetatehexane to give the title compound. LC/MS: (M+1)⁺: 393.24.

Step K:(1R,3′r,5S)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidin]-2′-one:To a solution of (1R,3′r,5S)-tert-butyl1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′-oxo-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidine]-9-carboxylate(0.22 g, 0.561 mmol) in methylene chloride (4 mL) was addedtrifluororoacetic acid (4 ml, 51.9 mmol), and the resulting solution wasstirred at rt for 2 h. After removing the volatiles the residue wasbasified on an ion exchange column washing with methanol followed byeluting with 1N ammonia in methanol to give the title compound. LC/MS:(M+1)⁺: 293.21.

Intermediate 54

6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(CIS, Faster)

Step A: ethyl 1-benzyl-4-(cyanomethyl)-3-oxopiperidine-4-carboxylate:Into a 250-mL 3-necked round-bottom flask was placed a solution of ethyl1-benzyl-3-oxopiperidine-4-carboxylate (10 g, 38.27 mmol, 1.00 equiv) intetrahydrofuran (80 mL). This was followed by the addition of a solutionof KHMDS in tetrahydrofuran (42 mL, 1M) dropwise with stirring at 0° C.,and 30 min later, 2-bromoacetonitrile (6.89 g, 57.44 mmol, 1.50 equiv)was added dropwise with stirring at 0° C. The resulting solution wasstirred for 4 h at room temperature. The resulting mixture wasconcentrated under vacuum. The residue was applied onto a silica gelcolumn and eluted with ethyl acetate/petroleum ether to give the titlecompound.

Step B: ethyl4-(2-aminoethyl)-1-benzyl-3-hydroxypiperidine-4-carboxylate: Into a10000-mL 4-necked round-bottom flask was placed a solution of ethyl1-benzyl-4-(cyanomethyl)-3-oxopiperidine-4-carboxylate (180 g, 599.30mmol) in acetic acid/methanol (1:1, 5.4 L) and platinum oxide (27 g,118.90 mmol). The flask was then flushed and charged with hydrogen andstirred overnight at room temperature. After filtration under nitrogenthrough CELITE®, the filtrate was concentrated under vacuum to give thetitle compound.

Step C: 8-benzyl-6-hydroxy-2,8-diazaspiro[4.5]decan-1-one: Into a10000-mL 3-necked round-bottom flask was placed a solution of ethyl4-(2-aminoethyl)-1-benzyl-3-hydroxypiperidine-4-carboxylate (220 g,718.02 mmol, 1.00 equiv) in methanol (2000 mL) and ammonia (2000 mL).The resulting solution was stirred overnight at 45° C. The resultingmixture was concentrated under vacuum. The residue was applied onto asilica gel column and eluted with dichloromethane/methanol to obtain thetitle compound.

Step D: cis-tert-butyl6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate:Into a 2000-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen was placed a solution of8-benzyl-6-hydroxy-2,8-diazaspiro[4.5]decan-1-one (46.3 g, 177.85 mmol,1.00 equiv), Cs₂CO₃ (115.9 g, 354.62 mmol, 1.99 equiv), Xantphos (6.17g, 10.66 mmol, 0.06 equiv), Pd₂(dba)₃ (5.52 g, 6.03 mmol, 0.03 equiv)and 4-methyl-5-oxo-2,5-dihydrofuran-3-yl trifluoromethanesulfonate(56.92 g, 231.23 mmol, 1.30 equiv) in dioxane (900 mL). The resultingsolution was stirred overnight at 80° C. The resulting mixture wascooled and concentrated under vacuum. The residue was diluted with 1000mL of water, then extracted with ethyl acetate. The organic layers werecombined, washed with 1000 mL of water and 1000 mL of brine, dried overanhydrous sodium sulfate and concentrated under vacuum. The residue wasapplied onto a silica gel column and eluted with ethyl acetate to giveof trans-tert-butyl6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate,LC/MS: (M+1)⁺: 357; ¹H-NMR (300 MHz, CDCl₃, ppm): δ 7.33-7.26 (5H, m),5.27-5.25 (2H, m), 4.04-3.96 (2H, m), 3.75-3.72 (1H, m), 3.58 (2H, d,J=2.4 Hz), 2.88-2.75 (3H, m), 2.55-2.50 (1H, m), 2.40-2.12 (3H, m),2.09-2.00 (4H, m), 1.57-1.55 (1H, m). and cis-tert-butyl6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate.LC/MS: (M+1)⁺: 357; ¹H-NMR (300 MHz, CDCl₃, ppm): δ 7.33-7.26 (5H, m),5.27-5.25 (2H, m), 4.06-3.94 (3H, m), 3.61-3.50 (2H, m), 2.93-2.81 (1H,m), 2.79-2.74 (1H, m), 2.57-2.48 (1H, m), 2.19-2.12 (2H, m), 2.03-2.02(3H, m), 1.97-1.85 (2H, m), 1.68-1.58 (2H, m).

Step D: tert-butyl6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(CIS): To a solution of8-benzyl-6-hydroxy-2-(2-methyl-3-oxocyclopent-1-en-1-yl)-2,8-diazaspiro[4.5]decan-1-one(CIS) (10 g, 28.2 mmol) and di-tert-butylcarbonate (7.21 ml, 31.0 mmol)in methanol (50 ml) was added palladium on carbon (1.501 g, 1.411 mmol),and the resulting mixture was subjected to hydrogenation at 45 Psi at rtover the weekend. The suspension was filtered through CELITE® undernitrogen, the filtrate was concentrated and the residue was purified onsilica gel using ethyl acetatehexane as eluting solvents to give thetitle compound. LC/MS: (M+1)⁺: 367.17.

Step E: tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(CIS, faster) and tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(CIS, slower): To the mixture of tert-butyl6-hydroxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (CIS)(2 g, 5.46 mmol) and silver oxide (1.391 g, 6.00 mmol) in acetonitrile(50 mL) was added methyl iodide (3.41 ml, 54.6 mmol). The mixture washeated at 60° C. in a sealed tube overnight. After it cooled to rt, themixture was filtered and the filtrate was concentrated and the residuewas purified by silica gel chromatography using ethyl acetatehexane togive tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(CIS, racemate). LC/MS: (M+1)⁺: 380.99. The racemate was furtherseparated on an AD chiral column give tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(faster eluting, CIS), LC/MS: (M+1)⁺: 381.05, and tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(slower eluting, CIS). LC/MS: (M+1)⁺: 381.01.

Step F:6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(CIS, faster): To a solution of tert-butyl6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate(CIS, faster) (2.17 g, 5.70 mmol) in methylene chloride (7 mL) was addedtrifluoroacetic (7 mL, 91 mmol) and the resulting solution was stirredat rt for 2 h. After concentration the residue was basified on ionexchange column washing with methanol first, then eluted with 1 Nammonia in methanol to give6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(CIS, faster). LC/MS: (M+1)⁺: 281.11.

In the following Examples and above Intermediates, isomer “A” and isomer“B,” (e.g., Isomer 6A and 6B, and the like), refer to the faster elutingand slower eluting diastereomers, respectively, based on the observedelution order of the individual diastereomers upon separation from itsisomer mixture. Except for a defined chiral center in the parent isomermixture, absolute stereochemistry of each of the separated isomers wasnot determined unless stated otherwise.

In examples where absolute stereochemistry of each of the separatedisomers was not determined, an asterisk (*) may be used in theassociated chemical structure drawing that indicates the location of theunassigned chiral center.

EXAMPLE 1

8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

A mixture of (4-Methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)acetaldehyde(I-3) (100 mg, crude) and2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-16) (145 mg, 0.58 mmol) in THF (5 mL) was stirred at rt for 2 hoursand then NaBH(OAc)₃ (167 mg, 0.79 mmol) was added to the mixture, whichwas further stirred at 50° C. for 3 hours. After quenching withsaturated NH₄Cl aq, the mixture was extracted with EtOAc and organiclayer was dried over Na₂SO₄. Solvent was removed under reduced pressureand the residue was purified by prep-TLC (EtOAc/MeOH: 1/1) and prep-HPLCto give the title product. MS (ESI) m/z: 425 (M+H⁺); ¹H NMR (400 MHz,MeOD): δ 7.69 (d, J=7.6 Hz, 1H), 7.50 (d, J=7.6 Hz, 1H), 5.38 (s, 2H),5.27-5.25 (m, 2H), 4.20-4.14 (m, 2H), 3.83-3.80 (m, 1H), 3.68-3.66 (m,1H), 3.42-3.38 (m, 2H), 3.33-3.23 (m, 4H), 2.41 (s, 3H), 2.39-2.30 (m,2H), 2.24-2.17 (m, 2H), 2.10-2.03 (m, 5H).

The following compounds in Table 1 were prepared in an analogous fashionto EXAMPLE 1 starting from piperidine and aldehyde intermediatesprepared as described above.

TABLE 1 Example Intermediates EXAMPLE STRUCTURE/NAME Characterization 25, 22A

LC/MS, (M + 1)⁺: 455 3 1, 16

LC/MS, (M + 1)⁺: 397 4 3, 22A

LC/MS, (M + 1)⁺: 425

EXAMPLE 5

8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one (I-16,200 mg, 0.846 mmol) was combined with4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one (I-4B) (177 mg,0.931 mmol) in ethanol (5 mL) and heated in a microwave apparatus at145° C. for 3 hours. The solvent was removed and the residue waspurified by preparative TLC, eluting with 25% methanol/EtOAc to affordthe title compound. LC-MS (IE, m/z): 427 (M+1)⁺.

EXAMPLE 6

8-((R)-2-Hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one3-Methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-22, 0.257 mmol) was dissolved in ethanol (3 mL), and treated withdiisopropylethylamine (135 μA, 0.771 mmol) followed by(R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (I-4B, 73.3 mg,0.385 mmol). The mixture was heated at 80° C. in a sealed tube for 12hours. The reaction mixture was then cooled to room temperature andconcentrated. The resulting crude product was purified by columnchromatography eluting with a 0-20% MeOH/EtOAc gradient to give thetitle product as a mixture of diastereomers. LC-MS (IE, m/z): 441.3(M+1)⁺.

EXAMPLE 6A and 6B (Separated Single Isomers)

-   (R)-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;    and-   (S)-8-((R)-2-Hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one    (separated isomers A and B):

The product of Example 6 was resolved using SFC eluting with 30% MeOH(0.2% DEA)/CO₂ on Chiralcel OD column to give Isomer 6A (fastereluting): LC-MS (IE, m/z): 441.3; and Isomer 6B (slower eluting): LC-MS(IE, m/z): 441.3 (M+1)⁺.

EXAMPLE 7

8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:A solution of2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-17, 6.00 g, 24.0 mmol) and4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one (I-4B, 5.93 g, 31.2mmol) in ethanol (20 mL) in a sealed tube was heated at 95° C.overnight. After concentration, the residue was purified on silica gelcolumn using methanol/dichloromethane, then precipitated from methanolto give the title compound. LC/MS, (M+1)⁺: 440.93. ¹HNMR (500 MHz,CDCl₃), δ7.845-7.809(m, 2H), 5.290-5.278(m, 4H), 5.139-5.112(m, 1H),4.072-4.044(t, J=7.1 Hz, 2H), 3.190-3.167(m, 1H), 2.876-2.859(m, 1H),2.636-2.604(m, 2H), 2.468-2.421(m, 1H), 2.311 (s, 3H), 2.350-2.328 (m,1H), 2.193-2.165(t, J=7.1 Hz, 2H), 2.101-2.039(m, 5H), 1.668-1.618(m,2H).

EXAMPLE 8

8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-17, 10 mg, 0.040 mmol) in ethanol (2 mL) in a microwave tube wasadded (S)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (I-4A, 9.9 mg,0.052 mmol)) and the resulting solution was heated at 140° C. inmicrowave for 3 h. After concentration, the residue was purified bypreparative TLC using 30% methanol/ethyl acetate to give the titlecompound. LC/MS, (M+1)⁺: 441.00, ¹HNMR (500 MHz, CDCl₃), δ7.840-7.804(m,2H), 5.304-5.240(m, 4H), 5.134-5.107(m, 1H), 4.066-4.038(t, J=7.1Hz,2H), 3.185-3.161(m, 1H), 2.8885-2.862(m, 1H), 2.629-2.568 (m, 2H),2.462-2.416(m, 1H), 2.305 (s, 3H), 2.344-2.323(m, 1H), 2.197-2.158(t,J=7.1 Hz, 2H), 2.108-2.033(m, 5H), 1.661-1.604(m, 2H).

EXAMPLE 9

9-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-9-azoniaspiro[5.5]undecane

To a solution of2-(4-Methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,9-diazaspiro[5.5]undecan-1-one(1-19, 50 mg, 0.19 mmol) in ethanol (2 mL) in a microwave tube was added(S)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (I-4B, 43.2 mg,0.227 mmol)) and the resulting solution was heated at 145° C. inmicrowave for 35 min. After concentration, the residue was purified bypreparative TLC (2000 Mm, 8% MeOH/EtOAc) to give the title compound as afree base. The free base was converted to the HCl salt by adding 1 M HClin ether (189 Ml, 0.189 mmol) and concentrating to dryness. LC/MS,(M+1)⁺: 455

The following compounds in Table 2 were prepared in an analogous fashionto EXAMPLES 5-9 starting from the indicated piperidine and epoxideintermediates prepared as described above.

TABLE 2 Interme- Example diates EXAMPLE STRUCTURE/NAME Characterization10 4B, 14

LC/MS, (M + 1)⁺: 413 11 12 4B, 26

LC/MS, (M + 1)⁺: 441 for each isomer 13 14 4B, 27

LC/MS, (M + 1)⁺: 455 for each isomer 15 4B, 20

LC/MS, (M + 1)⁺: 427 16 4B, 21

LC/MS, (M + 1)⁺: 441 17 4B, 23

LC/MS, (M + 1)⁺: 455 18 4B, 31

LC/MS, (M + 1)⁺: 453 19 4B, 30

LC/MS, (M + 1)⁺ 467 20 4B, 32

LC/MS, (M + 1)⁺: 467 21 4A, 16

LC/MS, (M + 1)⁺: 427 22 4B, 29

LC/MS, (M + 1)⁺: 445 23 4B, 18

LC/MS, (M + 1)⁺: 441 24 4B, 15

LC/MS, (M + 1)⁺: 427 25 4B, 28

LC/MS, (M + 1)⁺: 461, 463 26 4B, 35 polar

LC/MS, (M + 1)⁺: 457 27 28 4B, 36B

LC/MS, (M + 1)⁺: 459 for each isomer 29 30 4B, 42

LC/MS, (M + 1)⁺: 455 for each isomer 31 4B, 25

LC/MS, (M + 1)⁺: 467 32 33 4B, 37A 4B, 37B

LC/MS, (M + 1)⁺: 457 for each isomer 34 35 4B, 39A 4B, 39B

LC/MS, (M + 1)⁺: 471 for each isomer 36 4B, 38

LC/MS, (M + 1)⁺: 455 37 7B, 17

LC/MS, (M + 1)⁺: 441 38 7A, 17

LC/MS, (M + 1)⁺: 441 39 40 4B, 33A 4B, 33B

LC/MS, (M + 1)⁺: 467 for each isomer 41 42 4A, 33A 4A, 33B

LC/MS, (M + 1)⁺: 467 for each isomer 43 4B, 40

LC/MS, (M + 1)⁺: 441 44 4B, 41

LC/MS, (M + 1)⁺: 425 45 4B, 34

LC/MS, (M + 1)⁺: 496 46 4A, 34

LC/MS, (M + 1)⁺: 496

EXAMPLE 47

8-[(2R)-2-fluoro-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A:8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a suspension of 4-methyl-5-[(2S)-oxiran-2-yl]-2-benzofuran-1(3H)-one(I-4A)(200 mg, 1.05 mmol) and2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(300 mg, 1.05 mmol) in 10 mL of EtOH was added DIPEA (271 mg, 2.10mmol). The resulting mixture was stirred at 80° C. overnight, and thencooled to room temperature; the solvent was removed under vacuum. Theresidue was purified by flash chromatography (ethyl acetate: MeOH=20:1)to afford title compound. MS-ESI (m/z): 441 (M+1)

Step B:8-[(2R)-2-fluoro-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of the product of Step A, (170 mg, 0.39 mmol) in 5 mL ofDCM was added Et₃N.3HF (10 drops) and DAST (5 drops) at −78° C. Themixture was stirred overnight and quenched with aqueous NaHCO₃. Theorganic layer was separated and the aqueous was extracted with DCM. Thecombined organic layers were dried over anhydrous Na₂SO₄, filtered andthe solvent was removed under vacuum, the residue was purified bypreparative TLC (EtOAc: MeOH=1:1) to afford title compound. ¹H NMR (400MHz, CDCl₃): δ 7.81 (d, J=7.8 Hz, 1H), 7.61 (d, J=7.8 Hz, 1H), 6.02-5.88(m, 1H), 5.28-5.22 (m, 4H), 4.01 (t, J=7.0 Hz, 2H), 3.06-2.85 (m, 3H),2.73-2.61 (m, 1H), 2.46-2.38 (m, 2H), 2.31 (s, 3H), 2.11 (t, J=7.0 Hz,2H), 2.05-1.96 (m, 5H), 1.55-1.50 (m, 2H). MS-ESI (m/z): 443 (M+1)⁺.

EXAMPLE 48

8-[(2S)-2-fluoro-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared in an analogous fashion to thatdescribed immediately above for the synthesis of Example 47, exceptstarting from 4-methyl-5-[(2R)-oxiran-2-yl]-2-benzofuran-1(3H)-one(I-4B). ¹H NMR (400 MHz, CDCl₃): δ 7.81 (d, J=7.8 Hz, 1H), 7.61 (d,J=7.8 Hz, 1H), 6.02-5.88 (m, 1H), 5.28-5.23 (m, 4H), 4.01 (t, J=7.0 Hz,2H), 3.05-2.86 (m, 3H), 2.73-2.61 (m, 1H), 2.46-2.38 (m, 2H), 2.31 (s,3H), 2.13 (t, J=7.0 Hz, 2H), 2.05-1.96 (m, 5H), 1.55-1.50 (m, 2H).MS-ESI (m/z): 443 (M+1)⁺.

EXAMPLE 49

8-[(2R)-2-methoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane

Step A:(S)-8-(2-chloro-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Example 7) (1.1 g, 2.5 mmol) and methanesulfonyl chloride (0.584 mL,7.49 mmol) in DCM (30 mL) was added triethylamine (1.22 mL, 8.74 mmol)and N,N-dimethylpyridin-4-amine (0.031 g, 0.250 mmol) at −10 to −15° C.(ice-NaCl). The mixture was stirred at the same temperature for 20 min,quenched with NH₄Cl aqueous. The organic layer was separated, and theaqueous was extracted with DCM (30 mL). The combined organic layers weredried (MgSO₄) and concentrated under reduced pressure to give productwas used in the next step without further purification. LCMS: 459.05(M+1).

Step B:8-[(2R)-2-methoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane:One small piece of sodium metal in methanol (20 mL) was stirred untilthe sodium disappeared. The product of Step A (45 mg, 0.098 mmol) wasadded to the solution. The mixture was stirred at rt for 20 min. 3 mL 1N HCl was added, and the mixture was concentrated. The residue wasdissolved in DMSO, and was purified by Gilson reverse phase HPLC (3%-45%of 0.1% TFA-water in 0.1% TFA-AcCN) to give the title compound. ¹HNMR(500 MHz), δ 7.82 (1 H, d, J=7.6 Hz), 7.70 (1 H, d, J=7.8 Hz), 5.42 (2H, s), 5.28 (2 H, s), 5.20 (1 H, m), 4.15 (3 H, s), 3.50-3.90 (4 H, m),3.12-3.50 (4 H, m), 2.45 (3 H, s), 2.15-2.37 (4 H, m), 2.07 (3 H, s),1.95-2.05 (2 H, m). LC-MS 455.1 (M+1), 477.09 (M+23).

EXAMPLE 50

8-[(2R)-2-ethoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared using essentially the same procedure asExample 49 except for use of ethanol in place of methanol as thereaction solvent in Step B. LC-MS: 469.13 (M+1).

EXAMPLE 51

8-[(2R)-2-methoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

The title compound was prepared using essentially the same procedure asExample 49, except starting from8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one.LC-MS: 441 (M+1).

EXAMPLE 52

1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-8-[3-oxo-3,6,8,9-tetrahydro-1H-furo[3,4-f]isochromen-6-yl)methyl]-2-aza-8-azoniaspiro[4.5]decane:(3-oxo-3,6,8,9-tetrahydro-1H-furo[3,4-f]isochromen-6-yl)methyl-4-methylbenzenesulfonate(I-8) (80 mg, 0.21 mmol) was combined with2-(5-Oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one (I-16)(50.5 mg, 0.214 mmol) and triethylamine (30 μL, 0.21 mmol) inacetonitrile (2 mL) in a microwave tube and heated at 140° C. Thesolvent was removed and the residue was purified by MPLC eluting with 5%methanol/DCM to afford the title compound as a mixture of twoenantiomers. LC-MS: 439 (M+1).

EXAMPLES 53A, 53B, 53C, 53D (Four Individual Isomers)

-   8-((1S,2R)-1-hydroxy-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one-   8-((1R,2R)-1-hydroxy-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one-   8-((1R,2S)-1-hydroxy-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;    and-   8-((1S,2S)-1-hydroxy-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one    (Separated to Four Single Isomers)

To 5-(1,2-dihydroxypropyl)-4-methylisobenzofuran-1(3H)-one (I-6) (300mg, 1.35 mmol) and2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-17) (405 mg, 1.62 mmol) in t-amyl alcohol (2.7 mL) was added2-(dicyclohexylphosphino)-1-phenyl-1H-pyrrole (82 mg, 0.243 mmol) andruthenium carbonyl (51.8 mg, 0.081 mmol). The reaction mixture wasdegassed and heated at 140° C. for two days. The reaction mixture wasconcentrated and purified by column chromatography (0-10% MeOH/DCM) toseparate the syn and anti isomers. The resulting syn and anti isomerswere then respectively purified by SFC-HPLC, using the followingconditions: chiralpak AD, 30×250 mm, 65% MeOH+0.2% DEA, 70 mL/min togive four single isomers of the title compound. Absolute stereochemistryhas not been assigned with certainty for each isomer at this time. Theyare designated as follows: Isomer 53A: faster eluting from MeOH columnchromatography, faster eluting from SFC-HPLC; LC/MS: [(M+1)]⁺=455.Isomer 53B: faster eluting from MeOH column chromatography, slowereluting from SFC-HPLC; LC/MS: [(M+1)]⁺=455. Isomer 53C: slower elutingfrom MeOH column chromatography, faster eluting from SFC-HPLC; LC/MS:[(M+1)]⁺=455. Isomer 53D: slower eluting from MeOH columnchromatography, slower eluting from SFC-HPLC; LC/MS: [(M+1)]⁺=455

EXAMPLE 54

8-(2-(cyclopropylamino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A:8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-oxoethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-17) (2 g, 7.99 mmol),5-(2-Bromo-acetyl)-4-methyl-3H-isobenzofuran-1-one (I-4B, method 2, stepF) (2.150 g, 7.99 mmol) and N-ethyl-N-isopropylpropan-2-amine (3.48 mL,19.98 mmol) in DCM (50 mL) were stirred overnight at rt. The mixture waswashed with saturated ammonium chloride aqueous and brine, dried overMgSO₄, and concentrated under reduced pressure. The crude material wasused in the next step without further purification. ¹H-NMR (500 MHz,CDCl₃): δ ppm 7.83 (1H, d, J=7.8 Hz), 7.79 (1 H. , d, J=7.8 Hz), 5.34 (2H, s), 5.32 (2 H, s), 5.26 (2 H, s), 4.03 (2 H, t, J=7.0 Hz), 3.71 (1 H,m), 3.15 (1 H, m), 2.94 (2 H, m), 2.47 (2 H, t, J=7.0 Hz), 2.42 (3 H,s), 2.17 (2 H, m), 2.07 (3 H, s), 2.02 (2 H, m), 1.58 (2 H, m). LCMS438.9 (M+1).

Step B:8-(2-(cyclopropylamino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a mixture of8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-oxoethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(25 mg, 0.057 mmol) and cyclopropanamine (6.5 mg, 0.114 mmol) inanhydrous 5% HOAc/THF (1 mL) was added NaCNBH₃ (18 mg, 0.28 mmol). Thereaction was sealed and shaken at ambient temperature for 16 h. LCMSshowed that the product was formed. The reaction was quenched with water(0.5 mL) and the solvent was evaporated under reduced pressure. Theresidue was dissolved in DMSO (1.5 mL) and filtered. The crude productwas purified by using reversed-phase HPLC (Acetonitrile with 0.1% TFA:water with 0.1% TFA from 10% to 60%) to give the title compound. LC-MS(IE, m/z): 480 [M+1]⁺.

The Examples in the Table 3 below were prepared in a similar fashion to8-(2-(cyclopropylamino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-oneabove (Example 54, Step B) starting from8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-oxoethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Example 54, Step B) and the indicated amines.

TABLE 3 Characterization EXAMPLE Amine Structure LC-MS 55 2,2-difluoroethanamine

504 (M + H)⁺ 56 Cyclo butanamine

494 (M + H)⁺ 57 azetidine

480 (M + H)⁺ 58 2-methoxy ethanamine

498 (M + H)⁺ 59 3-amino propane- nitrile

493 (M + H)⁺

EXAMPLE 60

8-[2-(methylamino)-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

To a mixture of8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-oxoethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(25 mg, 0.057 mmol) and methyl amine (4 mg, 0.114 mmol) in anhydrous THFwas added Ti(O-iPr)₄(35 μL, 0.114 mmol). The reaction was sealed andshaken at ambient temperature for 16 hr. To this reaction, EtOH (200proof, 0.5 mL) was added followed by adding NaBH₄ (11 mg, 0.171 mmol)portion-wise within 30 min. The reaction was shaken for 3 hr andquenched with water (0.5 mL). The reaction was partitioned between EtOAc(4 mL×2) and ammonium (2N, 1.5 mL). The organic phase was combined andevaporated under reduced pressure. The residue was dissolved in DMSO(1.5 mL) and filtered. The crude product was purified by usingreversed-phase HPLC (Acetonitrile with 0.1% TFA: water with 0.1% TFAfrom 10% to 60%) to give the title compound. LC-MS (IE, m/z): 454[M+1]⁺.

EXAMPLE 61

(S)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A:(S)-8-(2-azido-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a suspension of8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Example 7, 300 mg, 0.68 mmol) and diphenylphosphoryl azide (578 mg,1.36 mmol) in a mixed solvent of toluene and dichloromethane (v:v, 10:1,11 mL) was added DBU (310 mg, 1.36 mmol). The reaction mixture wasstirred at 35° C. for 20 h. The solvent was removed by evaporation andthe residue was purified by flash column chromatography (0-100% ethylacetate in petroleum ether gradient) to afford the title compound. ¹HNMR (400 MHz, CDCl₃): δ 7.32 (d, J=8.0 Hz, 1H), 7.50 (d, J=8.0 Hz, 1H),5.20 (s, 2H), 5.18 (s, 2H), 4.94 (dd, J=4.0 Hz, 9.2 Hz, 1H), 3.94 (t,J=6.8 Hz, 2H), 2.88-2.85 (m, 2H), 2.72-2.67 (m, 1H), 2.54-2.50 (m, 1H),2.42-2.39 (m, 1H), 2.33-2.27 (m, 4H), 2.04 (t, J=6.8 Hz, 2H), 1.95 (s,3H), 1.94-1.87 (m, 2H), 1.51-1.47 (m, 2H); MS-ESI (m/z): 466 (M+1)⁺.

Step B:(S)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of(S)-8-(2-azido-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(200 mg, 0.43 mmol) in a mixed solvent of tetrahydrofuran and water(v:v, 12:1, 20 mL) was added triphenylphosphine (225 mg, 0.86 mmol)under nitrogen atmosphere. The reaction mixture was stirred at roomtemperature for 18 h. The solvent was removed by evaporation and theresidue was purified by preparative TLC (dichloromethane: methanol=10:1)to afford the title compound as a solid.

¹H NMR (400 MHz, CDCl₃): δ 7.86 (d, J=7.6 Hz, 1H), δ 7.53 (d, J=7.6 Hz,1H), 5.24 (s, 2H), 5.22 (s, 2H), 4.50 (dd, J=4.0 Hz, 8.8 Hz, 1H), 3.98(t, J=6.8 Hz, 2H), 3.04-3.01 (m, 1H), 2.81-2.78 (m, 1H), 2.40-2.34 (m,2H), 2.30 (s, 3H), 2.18-2.08 (m, 4H), 2.01 (s, 3H), 2.00-1.95 (m, 2H),1.51-1.47 (m, 2H); MS-ESI (m/z): 440 (M+1)⁺.

EXAMPLE 62

(R)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A:(R)-8-(2-azido-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a suspension of8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Example 8, 500 mg, 1.13 mmol) and diphenylphosphoryl azide (643 mg,1.36 mmol) in a mixed solvent of toluene and dichloromethane (v:v, 10:1,11 mL) was added DBU (343 mg, 2.26 mmol). The reaction mixture wasstirred at 35° C. for 20 h. The solvent was removed by evaporation andthe residue was purified by flash column chromatography (0-100% ethylacetate in petroleum ether) to afford the title compound. ¹H NMR (400MHz, CDCl₃): δ 7.78 (d, J=8.0 Hz, 1H), 7.55 (d, J=8.0 Hz, 1H), 5.26 (s,2H), 5.23 (s, 2H), 4.99 (dd, J=4.0 Hz, 9.2 Hz, 1H), 4.00 (t, J=6.8 Hz,2H), 2.95-2.87 (m, 2H), 2.78-2.73 (m, 1H), 2.60-2.57 (m, 1H), 2.48-2.43(m, 1H), 2.33 (s, 3H), 2.10 (t, J=6.8 Hz, 2H), 2.03-1.86 (m, 6H),1.51-1.48 (m, 2H); MS-ESI (m/z): 466 (M+1)⁺.

Step C:(R)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4,5]decan-1-one:To a solution of(R)-8-(2-azido-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(250 mg, 0.54 mmol) in a mixed solvent of tetrahydrofuran and water(v:v, 12:1, 20 mL) was added triphenylphosphine (283 mg, 1.08 mmol)under nitrogen atmosphere. The reaction mixture was stirred at roomtemperature for 18 h. The solvent was removed by evaporation and theresidue was purified by preparative TLC (dichloromethane: methanol=10:1)to afford the title compound. ¹H NMR (400 MHz, Methanol-d4): δ 7.80 (d,J=8.0 Hz, 1H), δ 7.66 (d, J=8.0 Hz, 1H), 5.40 (s, 2H), 5.24 (s, 2H),4.73 (dd, J=4.0 Hz, 8.8 Hz, 1H), 4.09 (t, J=6.8 Hz, 2H), 3.30-3.21 (m,1H), 2.98-2.91 (m, 1H), 2.87-2.81 (m, 1H), 2.70-2.66 (m, 1H), 2.55-2.47(m, 2H), 2.40 (s, 3H), 2.18-2.07 (m, 4H), 2.00 (s, 3H), 1.74-1.68 (m,2H). MS-ESI (m/z): 440 (M+1)⁺.

EXAMPLE 63

Methyl{(1R)-1-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)-2-[2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-8-yl]ethyl}carbamate

To a solution of(R)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(Example 62) (35 mg, 0.08 mmol) and triethylamine (17 μL, 0.12 mmol) indichloromethane (2 mL) was added methyl chloroformate (11 mg, 0.12 mmol)at 0° C. under nitrogen atmosphere. The reaction mixture was allowed towarm to room temperature and stir for 2 h. TLC indicated half ofstarting material remained. The reaction mixture was re-cooled to 0° C.and triethylamine (17 μL, 0.12 mmol) was added thereto, followed bymethyl chloroformate (11 mg, 0.12 mmol). The reaction mixture wasallowed to warm to room temperature and stirred for another 2 h. TLCshowed the reaction was complete. The resulting mixture was concentratedin vacuo. The residue was taken up into small amount of DCM and purifiedby preparative TLC (dichloromethane: methanol=15:1) to afford the titlecompound. MS-ESI (m/z): 498 (M+1)⁺.

EXAMPLE 64

(R)—N-(1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-(2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decan-8-yl)ethyl)methanesulfonamide

To a solution of(R)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(30 mg, 0.068 mmol) and triethylamine (29 μL, 0.20 mmol) in DCM (2 mL)was added methanesulfonyl chloride (5.3 μL, 0.068 mmol) at 0° C. undernitrogen atmosphere. The reaction mixture was allowed to warm to roomtemperature and stirred for 3 h. TLC indicated the reaction wascomplete. Evaporation of the solvent afforded the residue, which wastaken up into small amount of DCM and purified by preparative TLC(dichloromethane: methanol=10:1) to give the title compound. ¹H NMR (400MHz, CDCl₃): δ 7.63 (dd, J=8.0 Hz, J=8.8 Hz, 2H), 5.30 (s, 2H), 5.15 (s,2H), 4.95-4.92 (m, 1H), 4.00 (t, J=7.2 Hz, 2H), 2.94-2.91 (m, 1H),2.82-2.78 (m, 1H), 2.72 (s, 3H), 2.65-2.59 (m, 1H), 2.42-2.39 (m, 1H),2.38-2.24 (m, 4H), 2.21-2.18 (m, 1H), 2.07 (t, J=7.2 Hz, 2H), 1.92 (s,3H), 1.86-1.72 (m, 2H), 1.52-1.47 (m, 2H). MS-ESI (m/z): 518 (M+1)⁺.

EXAMPLE 65

1′-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-oxo-1-(5-oxo-2,5-dihydrofuran-3-yl)-1,2-dihydrospiro[indole-3,4′-piperidinium]

Step A:(R)-1′-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)spiro[indoline-3,4′-piperidin]-2-one:Commercially available spiro[indoline-3,4′-piperidin]-2-onehydrochloride (500 mg, 2.10 mmol) was combined with4-methyl-5-[(2S)-oxiran-2-yl]-2-benzofuran-1(3H)-one (I-4A) (398 mg,2.10 mmol) and DIEA (439 μL, 2.51 mmol) in ethanol (7 mL) and heated at80° C. for 3 h. The reaction mixture was concentrated and purified byMPLC eluting first with 30% ethyl acetatehexanes and then with 10%methanol/DCM to afford the title compound which was a mixture ofregioisomers. MS-ESI (m/z): 393 (M+1)⁺;

Step B:1′-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-oxo-1-(5-oxo-2,5-dihydrofuran-3-yl)-1,2-dihydrospiro[indole-3,4′-piperidinium]:(R)-1′-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)spiro[indoline-3,4′-piperidin]-2-one(502 mg, 1.28 mmol), 4-bromofuran-2-one (250 mg, 1.53 mmol), cesiumcarbonate (625 mg, 1.92 mmol), Pd(dba)₂ (37 mg, 0.064 mmol), Xantphos(111 mg, 0.192 mmol), were combined in a microwave vial in 5 mL oftoluene. The suspension was purged with nitrogen and heated at 90° C.overnight. The reaction mixture was filtered through CELITE® washingwith ethyl acetate and the filtrate was concentrated. The crude productwas purified by MPLC using an ethyl acetatehexanes gradient first, then10% methanol/DCM to elute the product. In order to separate the desiredproduct from impurities and regioisomers, the residue was furtherpurified by preparative TLC (10% methanol/DCM) and by SFC HPLC using achiralcel OD column. MS-ESI (m/z): 475 (M+1)⁺.

The following compounds in Table 4 were prepared in an analogous fashionto EXAMPLES 5-9 starting from the indicated piperidine and epoxideintermediates prepared as described above. In instances where mixturesof isomers were produced, SFC chiral HPLC was employed to separate theisomers using the HPLC column indicated.

TABLE 4 Interme- EXAMPLE diates EXAMPLE STRUCTURE/NAME Characterization66 67 4B, 43

LC/MS, (M + 1)⁺: 455 for each isomer 68 69 4B, 44

LC/MS, (M + 1)⁺: 467 for each isomer 70 4B, 45

LC/MS, (M + 1)⁺: 481 71 4B, 46

LC/MS, (M + 1)⁺: 471 72 4B, 47

LC/MS, (M + 1)⁺: 439 73 4B, 48

LC/MS, (M + 1)⁺: 453 74 75 49, 17

LC/MS, (M + 1)⁺: 455 for each isomer 76 77 50, 17

LC/MS, (M + 1)⁺: 467 for each isomer 78 79 51, 17

LC/MS, (M + 1)⁺: 461 for each isomer 80 81 52, 17

LC/MS, (M + 1)⁺: 445 for each isomer 82 4B, 53

LC/MS, (M + 1)⁺: 483 83 4B, 54 (cis)

LC/MS, (M + 1)⁺: 471

EXAMPLE 84A and 84B (Separated Single Isomers)

-   (S)-8-(1-hydroxy-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one    and-   (R)-8-(1-hydroxy-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: 5-(2,3-dihydroxypropyl)-4-methylisobenzofuran-1(3H)-one: To asolution of 4-methyl-5-prop-2-en-1-yl-2-benzofuran-1(3H)-one (see step Afor 1-3), (2.00 g, 10.6 mmol) in acetone (30 mL) and water (10 mL) wasadded OsO₄ (0.27 g, 1.06 mmol) and NMO (6.70 g, 11.7 mmol), the solutionwas stirred at 25° C. for 18 h. The reaction mixture was diluted withwater (30 mL) and the aqueous layer was extracted with CH₂Cl₂ (3×40 mL).The organic layers were combined, washed with brine (2×40 mL), driedwith MgSO₄, filtered and concentrated. The residue was purified by flashcolumn chromatography (0-10% methanol in dichloromethane) to give thetitle compound.

Step B:5-(3-((tert-butyldimethylsilyl)oxy)-2-hydroxypropyl)-4-methylisobenzofuran-1(3H)-one:To a solution of 5-(2,3-dihydroxypropyl)-4-methylisobenzofuran-1(3H)-one(2.00 g, 9.0 mmol) in dry DMF (20 mL) was added imidazole (1.20 g, 18.0mmol) and TBSCl (1.50 g, 9.9 mmol). After stirring at 25° C. for 2.5 h,the reaction mixture was diluted with CH₂Cl₂ (50 mL) and washed with H₂O(3×20 mL) and saturated NaHCO₃ (3×20 mL). The combined aqueous layerswere extracted five times with CH₂Cl₂ (20 mL). The combined organiclayers were washed with brine (3×30 mL), dried over Na₂SO₄, filtered andconcentrated. The residue was purified by flash column chromatography(0-60% ethyl acetate in petroleum ether) to give the title compound.

Step C:5-(3-((tert-butyldimethylsilyl)oxy)-2-oxopropyl)-4-methylisobenzofuran-1(3H)-one:To a solution of5-(3-((tert-butyldimethylsilyl)oxy)-2-hydroxypropyl)-4-methylisobenzofuran-1(3H)-one(1.00 g, 3.0 mmol) in CH₂Cl₂ (30 mL) was added Dess-Martin periodinane(6.30 g, 15.0 mmol). After stirring at 25° C. for 12 h, the reactionmixture was filtered through a short pad of SiO₂ with CH₂Cl₂ (100 mL) asthe eluting solvent. After concentrating, the residue was purified byflash column chromatography (0-60% ethyl acetate in petroleum ether) togive the title compound.

Step D:8-(1-((tert-butyldimethylsilyl)oxy)-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of5-(3-((tert-butyldimethylsilyl)oxy)-2-oxopropyl)-4-methylisobenzofuran-1(3H)-one(0.50 g, 1.5 mmol) in methanol (20 mL) was added2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(I-17) (0.45 g, 1.8 mmol) and titanium(IV) isopropoxide (2.10 g, 7.5mmol). After stirring at for room temperature 48 h, sodiumcyanoborohydride (190 mg, 3.0 mmol) was added and the reaction mixturewas stirred at room temperature for 20 h. The reaction mixture wasquenched with water (10 mL), and the resulting inorganic precipitate wasfiltered off and washed with methanol (50 mL). The filtrate was thenconcentrated and the crude product was dissolved in ethyl acetate,filtered to remove the remaining inorganic solids, and concentrated. Theresidue was purified by flash column chromatography (0-10% methanol indichloromethane) to give the title compound. LC-MS (ESI, m/z): 569[M+1]⁺.

Step E:8-(1-hydroxy-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of8-(1-((tert-butyldimethylsilyl)oxy)-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(0.10 g, 0.18 mmol) in DCM (3 mL) was added trifluoroacetic acid (3 mL)at 0° C. After stirring at room temperature for 24 h, solvent wasremoved under reduced pressure and the residue was purified bypreparative-HPLC to give the title compound, which was separated by SFCchiral chromatography into two single enantiomers Isomer A (fastereluting) and Isomer B (slower eluting. Column: CHIRALPAK AD 250×30 mmI.D., 20 μm; Mobile phase: Supercritical CO₂EtOH (0.2% NH₃H₂O)=45/55;Flow rate: 80 ml/min. For both isomers: LC-MS (ESI, m/z): 455 [M+1]⁺.

EXAMPLE 85A and 85B (Separated Single Isomers)

-   (S)-8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one,    and-   (R)-8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one

Step A: 2,8-diazaspiro[4.5]decan-1-one: To a solution of tert-butyl1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (I-11) (5.0 g, 19.7 mmol)in methylene chloride (10 mL) was added trifluoroacetic acid (15.2 mL,197 mmol) and the resulting solution was stirred at rt for 1 h. Afterevaporating the volatiles the residue was basified on ion exchangecolumn washed with methanol followed by 1 N ammonia in methanol to give2,8-diazaspiro[4.5]decan-1-one. LC/MS: (M+1)⁺: 155.11

Step B: ethyl2-methyl-2-(1-oxo-2,8-diazaspiro[4.5]decan-8-yl)propanoate: A mixture of2,8-diazaspiro[4.5]decan-1-one (3.03 g, 19.65 mmol), triethylamine (5.48ml, 39.3 mmol) and ethyl 2-bromo-2-methylpropanoate (5.77 ml, 39.3 mmol)was heated at 80° C. overnight. The reaction mixture was partitionedbetween methylene chloride (200 mL) and saturated sodium bicarbonate,the alkaline phase was extracted with methylene chloride (3×100 mL). Thecombined organic phase was dried over magnesium sulfate, concentratedand the residue was purified on silica gel using methanol/methylenechloride to give the title compound. LC/MS (M+1)⁺: 269.4

Step C: 2-methyl-2-(1-oxo-2,8-diazaspiro[4.5]decan-8-yl)propanal: To asolution of ethyl2-methyl-2-(1-oxo-2,8-diazaspiro[4.5]decan-8-yl)propanoate (3.77 g, 14.1mmol) in toluene (100 mL) at −78° C. was added DIBAL-H (45.0 mL, 45.0mmol) dropwise. After 2 h, the reaction was quenched by addition ofmethanol (10 mL) dropwise, after warmed to rt, 30 mL of saturated sodiumsulfate solution was added and the mixture was vigorously stirred at rtfor 1 h. After filtration, the filtrate and the filter cake werepartitioned between DCM and saturated sodium bicarbonate, the alkalinephase was extracted with DCM three times, the combined organic phase wasdried over sodium sulfate, concentrated to give the title compound.LC/MS (M+1+18)⁺: 243.3; (M+1+32)⁺: 257.4.

Step D: 4-methyl-5-(trimethylstannyl)isobenzofuran-1(3H)-one: The asolution of4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yltrifluoromethanesulfonate(5.0 g, 16.9 mmol), lithium chloride (4.29 g, 101 mmol), andtetrakis(triphenylphosphine)palladium(0) (1.951 g, 1.688 mmol) indioxane (30 ml) in sealed tube was degassed with nitrogen for 0.5 hbefore addition of hexamethylditin (5.25 mL, 25.3 mmol), the tube wassealed and heating at 100° C. overnight. After filtration throughCELITE®, the filtrate was concentrated and the residue was purifiedsilica gel column using ethyl acetatehexane to give4-methyl-5-(trimethylstannyl)isobenzofuran-1(3H)-one. LC/MS: (M+1)⁺:308.99; 310.87; 312.78.

Step E: 5-bromo-4-methylisobenzofuran-1(3H)-one: To a solution of4-methyl-5-(trimethylstannyl)isobenzofuran-1(3H)-one (4.37 g, 14.05mmol) in DCM (20 mL) was added bromine (0.796 ml, 15.46 mmol) at 0° C.The reaction mixture was stirred at 0° C. for 0.5 h. Saturatedthiosulfate solution was added and the mixture was extracted withmethylene chloride (2×100 mL), the combined organic phase was dried oversodium sulfate, concentrated to give5-bromo-4-methylisobenzofuran-1(3H)-one. LC/MS: (M+1)⁺: 226.89; 228.89.

Step F: 5-bromo-4-methyl-1,3-dihydroisobenzofuran-1-ol: To a solution of5-bromo-4-methylisobenzofuran-1(3H)-one (3.45 g, 15.19 mmol) in toluene(100 mL) at −78° C. was added DIBAL-H (21.27 mL, 21.27 mmol) dropwise.After stirring at −78° C. for 2 h, the reaction was quenched by methanolat −78° C., then warmed to rt, then 20 mL of saturated sodium sulfatewas added and the mixture was vigorously stirred at rt for 30 min. Next,the mixture was filtered and washed with ethyl acetate. The filtrate waswashed with saturated sodium bicarbonate, dried over sodium sulfate,then concentrated to give the title compound. LC/MS: (M−17)⁺: 210.92;212.91.

Step G:((5-bromo-4-methyl-1,3-dihydroisobenzofuran-1-yl)oxy)(tert-butyl)dimethylsilane

A solution of TBS-Cl (3.63 g, 24.10 mmol) in methylene chloride (15 mL)was added to a solution of5-bromo-4-methyl-1,3-dihydroisobenzofuran-1-ol (2.76 g, 12.1 mmol) andimidazole (1.72 g, 25.3 mmol) in methylene chloride (80 mL) at 0° C.,the resulting solution was stirred at rt overnight. The mixture waspartitioned between DCM and water, the water phase was extracted withmethylene chloride and the combined organic phase was dried over sodiumsulfate then concentrated, and the residue was purified on silica gelcolumn using ethyl acetatehexane to give the title compound. LC/MS:(M−131)⁺: 210.91; 212.91.

Step H:8-(1-(1-((tert-butyldimethylsilyl)oxy)-4-methyl-1,3-dihydroisobenzofuran-5-yl)-1-hydroxy-2-methylpropan-2-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of((5-bromo-4-methyl-1,3-dihydroisobenzofuran-1-yl)oxy)(tert-butyl)dimethylsilan(3.9 g, 11.36 mmol) in tetrahydrofuran (50 ml) at −78° C. was addedN-butyllithium (5.00 ml, 12.50 mmol). After 15 min,2-methyl-2-(1-oxo-2,8-diazaspiro[4.5]decan-8-yl)propanal (0.892 g, 3.98mmol) was added in one portion. The resulting solution was stirred at−78° C. for 3.5 h before being quenched by addition of methanol (6 mL)and saturated sodium bicarbonate (100 mL). The mixture was extractedwith 30% isopropanol/methylene chloride (3×100 mL). The combined organicphase was dried over sodium sulfate, concentrated and the residue waspurified on silica gel using methanol/methylene chloride to give thetitle compound. LC/MS: (M+1)⁺: 489.15.

Step I:8-(1-(1-((tert-butyldimethylsilyl)oxy)-4-methyl-1,3-dihydroisobenzofuran-5-yl)-1-hydroxy-2-methylpropan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a mixture of8-(1-(1-((tert-butyldimethylsilyl)oxy)-4-methyl-1,3-dihydroisobenzofuran-5-yl)-1-hydroxy-2-methylpropan-2-yl)-2,8-diazaspiro[4.5]decan-1-one(1.35 g, 2.76 mmol), 4-methyl-5-oxo-2,5-dihydrofuran-3-yltrifluoromethanesulfonate (I-9) (0.884 g, 3.59 mmol) in toluene (40 mL)was added potassium carbonate (0.764 g, 5.52 mmol), Xantphos (0.320 g,0.552 mmol), and water (0.149 mL, 8.29 mmol). The mixture was flushedwith nitrogen for 20 min before addition of palladium (II) acetate(0.062 g, 0.276 mmol). The resulting mixture was heated at 70° C.overnight. After filtration the filtrate was concentrated and theresidue was purified on silica gel column using methanol/methylenechloride as eluting solvents to give the title compound. LC/MS:(M+1−114)⁺:471.22.

Step J:8-(1-hydroxy-1-(1-hydroxy-4-methyl-1,3-dihydroisobenzofuran-5-yl)-2-methylpropan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of the product of Step I (1.282 g, 2.192 mmol) intetrahydrofuran (50 ml) was added TBAF (2.63 mL, 2.63 mmol) at 0° C.,and the resulting solution was stirred at 0° C. for 2 h. Afterconcentration, the residue was purified on TLC eluting with 10% MeOH/DCMto give the title compound. LC/MS: (M+1)⁺: 471.20.

Step K:8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:To a solution of the product of Step J (340 mg, 0.723 mmol) in methylenechloride (30 mL) was added PCC (311 mg, 1.45 mmol) at 0° C. and theresulting solution was stirred at 0° C. for 2 h. The reaction mixturewas partitioned between methylene chloride and saturated bicarbonate,and the alkaline phase was extracted with methylene chloride (3×50 mL).The combined organic phase was dried over sodium sulfate, concentratedand the residue was purified on TLC using 10% methanol/methylenechloride as developing solvents to give the title compound. LC/MS:(M+1)⁺: 469.20.

Step L:8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one(separated single isomers): The title compound (an isomer mixture) (100mg, 0.213 mmol) was separated by SFC on OJ column to give two isomers.Isomer A (faster eluting): LC/MS: (M+1)⁺: 469.25; ¹HNMR (500 MHz,CDCl₃), δ 7.766-7.289 (m, 2H), 5.287 (s, 2H), 5.261(s, 2H), 5.139 (s,1H), 4.072-4.044(t, J=7.1 Hz, 2H), 3.190-3.088(m, 2H), 2.545-2.506(m,2H), 2.341(s, 3H), 2.191-2.162(m, 2H), 2.066-2.037(m, 2H),1.695-1.670(m, 2H), 0.985(s, 3H), 0.956(s, 3H). Isomer B (slowereluting), LC/MS: (M+1)⁺: 469.25. ¹HNMR (500 MHz, CDCl₃), δ7.825-7.768(m,2H), 5.289(s, 2H), 5.262(s, 2H), 5.138(s, 1H), 4.073-4.044(t, J=6.9 Hz,2H), 3.191-3.086(m, 2H), 2.592-2.502(m, 2H), 2.341(s, 3H),2.191-2.162(m, 2H), 2.066-2.037(m, 2H), 1.695-1.670(m, 2H), 0.985(s,3H), 0.956(s, 3H).

The following Thallium Flux Assay and/or the Electrophysiology Assaywere performed on each of the final product compounds in the Examplesunless otherwise noted in an Example.

Thallium Flux Assay

Cell Culture Conditions— HEK293 cells stably expressing hROMK(hK_(ir)1.1) were grown at 37° C. in a 10% CO₂ humidified incubator incomplete growth media: Dulbecco's Modified Eagle Medium supplementedwith non-essential amino acids, Penicillin/Streptomycin/Glutamine, G418and FBS. At >80% confluency, aspirate the media from the flask and rinsewith 10 mL Calcium/Magnesium-free PBS. Add 5 mL of 1× trypsin (preparedin Ca/Mg Free PBS) to T-225 flask and return flask to 37° C./CO₂incubator for 2-3 minutes. To dislodge the cell, gently bang the side ofthe flask with your hand. Triturate the cells completely and thentransfer the cells to 25 mL complete media. Centrifuge at 1,500 rpm for6 min followed by resuspension in complete growth media and determinecell concentration. For typical re-seeding, 4E6 cells/T-225 flask willattain >80% confluency in 4 days. Under ideal growth conditions andappropriate tissue culture practices, this cell line is stable for 40-45passages.

FluxOR Kit Components (Invitrogen F10017)

-   -   FluxOR™ Reagent (Component A)    -   FluxOR™ Assay Buffer (Component B)—10× Concentrate    -   PowerLoad™ Concentrate (Component C)—100× Concentrate    -   Probenecid (Component D)—Lyophilized sample is kept at −20° C.        Water soluble, 100×after solubilization in 1 mL water. Store at        4° C.    -   FluxOR™ Chloride-free Buffer (Component E)—5× Concentrate    -   Potassium sulfate (K₂SO₄) Concentrate (Component F)—125 mM in        water. Store at 4° C.    -   Thallium sulfate (Tl₂SO₄) Concentrate (Component G)—50 mM in        water. Store at 4° C.    -   DMSO (dimethyl sulfoxide, Component H)—1 mL (100%)        Reagent Preparation: FluxOR Working Solutions    -   1000× FluxOR™ Reagent: Reconstitute a vial of component A in 100        μl DMSO; Mix well; Store 10 μl aliquots at −20° C.    -   1× FluxOR™ Assay Buffer: Dilute Component B 10-fold with water;        Adjust pH to 7.4 with Hepes/NaOH; Filter and store at 4° C.    -   Probenecid/Assay Buffer: 100 mL of 1× FluxOR™ Assay Buffer; 1 mL        of reconstituted component D; Store at 4° C.    -   Loading Buffer (per microplate): 10 μl 1000× FluxOR™ Reagent;        100 μl component C; 10 mL Probenecid/Assay Buffer    -   Compound Buffer (per microplate): 20 mL Probenecid/Assay Buffer;        0.3 mM ouabain (10 mM ouabain in water can be stored in amber        bottle/aluminum foil at room temperature); Test compound    -   1× FluxOR™ Chloride-Free Buffer: Prepare 1× working solution in        water. Can be stored at room temperature    -   Stimulant Buffer (prepared at 5× final concentration in 1×        FluxOR™ Chloride-Free Buffer): 7.5 mM Thallium sulfate and 0.75        mM Potassium sulfate (to give a final assay concentration of 3        mM Thallium 0.3 mM Potassium). Store at 4° C. when not in use.        If kept sterile, this solution is good for months.

Assay Protocol—The ROMK channel functional thallium flux assay isperformed in 384 wells, using the FLIPR-Tetra instrument. HEK-hKir1.1cells are seeded in Poly-D-Lysine microplates and kept in a 37° C.-10%CO₂ incubator overnight. On the day of the experiment, the growth mediais replaced with the FluxOR™ reagent loading buffer and incubated,protected from light, at ambient temperature (23-25° C.) for 90 min. Theloading buffer is replaced with assay buffer±test compound followed by30 min incubation at ambient temperature, where the Thallium/Potassiumstimulant is added to the microplate.

Step Protocol

-   1. Seed HEK-hKir1.1 cells (50 μA at 20,000 cells/well) in 384-well    PDL coated Microplates-   2. Allow cells to adhere overnight in humidified 37° C./10% CO₂    incubator-   3. Completely remove cell growth media from microplate and replace    with 25 μl loading buffer-   4. Incubate Microplate at room temperature, protected form light,    for 90 min-   5. Remove loading buffer and replace with 25 μl 1× Assay Buffer±test    compound.-   6. Incubate microplate at room temperature, protected from light,    for 30 min-   7. At FLIPR-Tetra 384: Add stimulant (Thallium/Potassium) solution    to microplate and monitor fluorescence. Excitation=400 nm,    Emission=460 & 580 nm. Collect data for 10 min.

Data Calculation—The fluorescence intensity of wells containing 3 μM ofa standard control ROMK inhibitor of the present invention is used todefine the ROMK-sensitive component of thallium flux. Fluorescence inthe presence of test compounds is normalized to control values toprovide % fluorescence change. IC₅₀ values represent the concentrationof compound that inhibits 50% of the ROMK thallium flux signal.

Assay Standard—Normally, a control compound is included to support thatthe assay is giving consistent results compared to previousmeasurements, although the control is not required to obtain the resultsfor the test compounds. The control can be any compound of Formula I ofthe present invention, preferably with an IC₅₀ potency of less than 1 μMin this assay. Alternatively, the control could be another compound(outside the scope of Formula I) that has an IC₅₀ potency in this assayof less than 1 μM.

Electrophysiology Assay

Block of Kir1.1 (ROMK1) currents was examined by whole cell voltageclamp (Hamill et. al. Pfluegers Archives 391:85-100 (1981)) using theIonWorks Quattro automated electrophysiology platform (MolecularDevices, Sunnyvale, Calif.). Chinese hamster ovary cells stablyexpressing Kir1.1 channels were maintained in T-75 flasks in cellculture media in a humidified 10% CO₂ incubator at 37° C. Prior to anexperiment, Kir1.1 expression was induced by overnight incubation with 1mM sodium butyrate. On the day of the experiment, cells were dissociatedwith 2.5 mL of Versene (Invitrogen 15040-066) for approximately 6 min at37° C. and suspended in 10 mL of bath solution containing (in mM): 150NaCl, 10 KCl, 2.7 CaCl₂, 0.5 MgCl₂, 5 HEPES, pH 7.4. Aftercentrifugation, the cell pellet was resuspended in approximately 4.0 mLof bath solution and placed in the IonWorks instrument. Theintracellular solution consisted of (in mM): 80 K gluconate, 40 KCl, 20KF, 3.2 MgCl₂, 3 EGTA, 5 Hepes, pH 7.4. Electrical access to thecytoplasm was achieved by perforation in 0.13 mg/mL amphotericin B for 4min. Amphotericin B (Sigma A-4888) was prepared as a 40 mg/mL solutionin DMSO. Voltage protocols and current recordings were performed usingthe IonWorks HT software/hardware system. Currents were sampled at 1kHz. No correction for liquid junction potentials was used. The testpulse, consisting of a 100 ms step to 0 mV from a holding potential of−70 mV, followed by a 100 ms voltage ramp from −70 mV to +70 mV, wasapplied before and after a 6 min compound incubation period. Testcompounds were prepared by diluting DMSO stock solutions into the bathsolution at 3× the final concentration and placed in the instrument in96-well polypropylene plates. Current amplitudes were measured using theIonWorks software. To assess compound potency, the fractional blockduring the voltage step to 0 mV was calculated in Microsoft Excel(Microsoft, Redmond, Calif.), and dose-response curves were fitted withIgor Pro 4.0 (WaveMetrics, Lake Oswego, Oreg.). Normally, a controlcompound is included to support that the assay is giving consistentresults compared to previous measurements, although the control is notrequired to obtain the results for the test compounds. The control canbe any compound of Formulas I-V of the present invention, preferablywith an IC₅₀ potency of less than 1 μM in this assay. Alternatively, thecontrol could be another compound (outside the scope of Formulas I-V)that has an IC₅₀ potency in this assay of less than 1 μM.

Data collected for compounds in the Examples of the present inventionusing the Thallium Flux Assay and the Electrophysiology Assay are shownin Table 5 below. All of the tested final product compounds in theExamples (diastereomeric mixtures and individual diastereomers) had IC₅₀potencies less than 1 μM in one or both of the Thallium Flux Assay andthe Electrophysiology Assay.

TABLE 5 EXAMPLE Thallium Flux IC₅₀ Electrophysiology IC₅₀ No. (μM) (μM) 1 0.01  2 0.05  3 0.29 0.07  5 0.03 0.004  6 0.03   6A 0.02   6B 0.01 7 0.02 0.01  8 0.03  9 0.01 0.01 10 0.20 0.03 11 0.12 0.02 12 0.14 0.0313 0.49 0.06 14 0.38 0.10 15 0.17 0.05 16 0.11 17 0.08 0.02 18 0.020.004 19 0.04 20 0.01 21 0.37 0.39 22 0.03 0.004 23 0.02 0.01 24 0.240.62 25 0.01 0.01 26 0.23 27 0.21 28 0.19 29 0.07 30 0.02 0.02 31 0.0434 0.09 35 0.07 36 0.03 37 0.03 38 0.02 39 0.02 40 0.02 41 0.24 42 0.1043 0.03 44 0.04 45 0.16 46 0.14 47 0.04 48 0.02 49 0.04 50 0.03 51 0.310.02 52 0.35 0.06   53A 0.01   53B 0.05   53C 0.01 0.01   53D 0.07 540.15 55 0.25 56 0.37 57 0.32 58 0.22 59 0.21 60 0.10 65 0.04 66 0.010.02 67 0.02 0.02 69 0.02 0.03 70 0.34 71 0.07 72 0.03 73 0.08 74 0.2075 0.03 0.01 76 0.01 0.01 77 0.24 78 0.27 79 0.01 0.003 80 0.05 0.01 810.19 82 0.18 83 0.04 0.05   84A 0.06   84B 0.07   85A 0.12   85B 0.01

Spontaneously Hypertensive Rat (SHR) Assay

The spontaneously hypertensive rat (SHR) exhibits age-dependenthypertension that does not require administration of exogenous agents toelevate blood pressure nor does it require the use of a high salt dietto elevate blood pressure. Thus it resembles human essentialhypertension and provides an opportunity to assess the dose-dependenceof novel agents for their ability to lower blood pressure.

Experimental protocols for evaluating blood pressure lowering efficacyof compounds of the present invention in spontaneuously hypertensiverats (SHR):

Spontaneously hypertensive rats (SHR, male, 6 months, Charles River)were implanted with DSI TA11PA-C40 telemetry device (Data Sciences,Inc., St. Paul, Minn.) under isoflurane or ketamine/metomidineanesthesia. The telemetry unit catheter was inserted into the descendingaorta via the femoral artery and the telemetry device was implantedsubcutaneously in the left flank area. Animals were allowed to recoverfrom surgery for 14 days before the start of any studies. Bloodpressure, heart rate, and activity signals from conscious, freely movingrats were recorded continuously for 30 seconds every 10 minutes. HCTZ(25 mg/kg/day, PO) was included as a reference diuretic at a dose givingapproximately maximal efficacy in SHR. The blood pressure loweringefficacy of compounds of the present invention compared to vehiclecontrol was evaluated following a single oral gavage each day for atypical duration of three to fourteen days. Data were collected ashourly averages, and changes in blood pressure were calculated bysubtracting vehicle control baseline data on an hourly basis. Examplenumbers 5, 7, 9 and 43 were evaluated at PO, QD doses at one or moredoses within the range of 0.3 to 10 mg/kg and resulted in typicalreductions in daily (24 h) mean systolic blood pressure ranging from 6mmHg to 24 mmHg at the doses used by the last day of the studies.

The Spontaneously Hypertensive Rat Assay is well known and often used inthe art as an experimental model simulating human hypertension (see,e.g., Lerman, L. O., et al., J Lab Clin Med, 2005; 146:160-173).

While the invention has been described with reference to certainparticular embodiments thereof, numerous alternative embodiments will beapparent to those skilled in the art from the teachings describedherein. The scope of the claims should not be limited by the preferredembodiments set forth in the examples, but should be given the broadestinterpretation consistent with the description as a whole. Recitation ordepiction of a specific compound in the claims (i.e., a species) withouta specific stereoconfiguration designation, or with such a designationfor less than all chiral centers, is intended to encompass the racemate,racemic mixtures, each individual enantiomer, a diastereoisomericmixture and each individual diastereomer of the compound where suchforms are possible due to the presence of one or more asymmetriccenters. All patents, patent applications and publications cited hereinare incorporated by reference in their entirety.

What is claimed is:
 1. A method for the treatment of one or moredisorders selected from hypertension, acute heart failure, chronic heartfailure or pulmonary arterial hypertension in a patient in need thereofby administering to the patient a therapeutically effective amount of acompound having structural Formula I

or a pharmaceutically acceptable salt thereof wherein: R¹ is —H, halo,—OH, or —OC₁₋₃alkyl; m is an integer selected from zero (R^(3b) isabsent) and 1 (R^(3b) is present); n is an integer selected from 1 or 2;R² is independently selected at each occurrence from —H, ═O (oxo), —OH,—C₁₋₃alkyl or —OC₁₋₃alkyl, provided that when n is 2, then at least oneR² is —H; R^(3a) is —H, ═O, —C₃₋₄cycloalkyl or —C₁₋₃alkyl optionallysubstituted with —OCH₃ or 1 to 3 of —F, provided that only one of R² orR^(3a) can be ═O, R^(3b) is —H or —C₁₋₃alkyl, or R^(3b) is absent whenR^(3a) is ═O or when the dashed bond is a double bond or an aromaticbond; R⁴ is —H or ═O; R⁵ is (a) —H, (b) halo, (c) —C₁₋₃alkyl optionallysubstituted with —O—C₁₋₃alkyl, or (d) —C₃₋₆cycloalkyl; R⁶ is —H or—C₁₋₃alkyl; R^(7a) is —H or —C₁₋₃alkyl optionally substituted with —OH,—OCH₃ or 1 to 3 of —F; R^(7b) is —H or —C₁₋₃alkyl; R⁸ is —H, halo or—C₁₋₃alkyl; R⁹ is —H, —F, —OH, —OC ₁₋₃alkyl, —CH₂OH, —NH—R¹³ or

R¹⁰ is —H, halo, —CN, —C₃₋₄ cycloalkyl, or —C₁₋₃alkyl optionallysubstituted with 1 to 3 of —F; or R⁹ is —O —and is joined together withR¹⁰ to represent —CH₂—CH₂—O —; R¹¹ is —H, —CH₂OH, —CH₂OCH₃, or—C₁₋₃alkyl optionally substituted with 1 to 3 of —F; R¹² is —H, —CH²OH,—CH²OCH³, or —C¹⁻³alkyl optionally substituted with 1 to 3 of —F; or R¹¹and R¹² are joined together to represent —CH₂—CH₂—, —CH₂—N(CH₃)—CH₂— or—CH₂OCH₂—; R¹³ is —H, —(CH₂)₀₋₂—C ₃₋₆cycloalkyl,—(CH₂)₁₋₂—OC₃₋₆cycloalkyl, —(CH₂)₁₋₂—OC₃₋₆cycloalkyl,—(CH₂)₁₋₂—OC₁₋₃alkyl, —(CH²)₁₋₂—CN,—C(O)OC₁₋₃alkyl, —SO₂CH₃ or—C₁₋₃alkyl optionally substituted with one to three of —F; and thedashed bond (“- - -”) represents a single, double or aromatic bond,provided that (A) when n is 2, then the dashed bond is a single bond andm is 1; and (B) when n is 1 and (i) m is 1, or (ii) R^(3a) is ═O and mis zero, then the dashed bond is a single bond; and (C) when n is 1, mis zero, R² is not ═O and R^(3a) is not ═O, then the dashed bond is adouble bond.
 2. The method of claim 1 wherein the compound hasstructural Formula II or III or a pharmaceutically acceptable saltthereof:


3. The method of claim 2 wherein: R^(3a) is —H or —CH₃; R⁴ is ═O; R⁵ is—H or —CH₃; R^(7a) is —H or CH₃; R⁹ is —H, —OH, —OCH₃ or —NH₂; and R¹⁰is —H or —CH₃.
 4. The method of claim 3 wherein R⁹ is —OH; and R¹⁰ is—CH₃.
 5. The method of claim 1 wherein the compound has structuralFormula IV or a pharmaceutically acceptable salt thereof:


6. The method of claim 5 wherein: R^(3a) is —H or —CH₃; R⁴ is ═O; R⁵ is—H or —CH₃; R^(7a) is —H or CH₃; R⁹ is —H, —OH, —OCH₃ or —NH₂; and R¹⁰is —H or —CH₃.
 7. The method of claim 6 wherein R⁹ is —OH; and R¹⁰ is—CH₃.
 8. The method of claim 1 wherein the compound is:8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)8-((R)-2methoxy2(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[2-(1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)-3-methyl-8-(2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(R)-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one:8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;9-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-9-azoniaspiro[5.5]undecane;5-{(1R)-1-hydroxy-2-[2(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-8-yl]ethyl}-4-methyl-2-benzofuran-1(3H)-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(2-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;2-(2,4-dimethyl-5-oxo-2,5-dihydrofuran-3-yl)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-3-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-3-one;2-(4-ethyl-5-oxo-2,5-dihydrofuran-3-yl)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2,8-diazaspiro[4.5]decan-1-one;(1R,3r,5S)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-1′-(5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[8-azabicyclo[3.2.1]octane-3,3′-pyrrolidin]-2 ′-one;(1R,3r,5S)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[8-azabicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one;(1R,3s,5S)-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-8-azaspiro[bicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one;8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;2-(4-fluoro-5-oxo-2,5-dihydrofuran-3-yl)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-1-oxo-2-aza-8-azoniaspiro[4.5]decane;9-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2-aza-9-azoniaspiro[5.5]undecane;9-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2(5-oxo-2,5-dihydrofuran-3-yl)-2-aza-9-azoniaspiro[5.5]undecane;2-(4-chloro-5-oxo-2,5-dihydrofuran-3-yl)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-1-oxo-2-aza-8-azoniaspiro[4.5]decane;6-hydroxy-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane;6-fluoro-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-3-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;2-(4-cyclopropyl-5-oxo-2,5-dihydrofuran-3-yl)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2,8-diazaspiro[4.5]decan-1-one;4-hydroxy-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane;8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-4-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1,4-dioxo-2-aza-8-azoniaspiro[4.5]decane;8-[(2S)-2-hydroxy-2-(6-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane;8-[(2R)-2-hydroxy-2-(6-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane;(1R,3r,5S)-8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-5′-methyl-1-(5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[8-azabicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one;(1R,3r,5S)-8-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-5′-methyl-1′-(5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[8-azabicyclo[3.2.1]octane-3,3′-pyrrolidin]-2′-one;8-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]dec-3-ene;(R)-8-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one;(1R,3′s,5S)-9-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-ypethyl]-7-methyl-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[7,9-diazabicyclo[3.3.1]nonane-3,3′-pyrrolidin]-2′-one;(1R,3′s,5S)-9-[(2S)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-7-methyl-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2′H-spiro[7,9-diazabicyclo[3.3.1]nonane-3,3′-pyrrolidin]-2′-one;8-[(2R)-2-fluoro-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2S)-2-fluoro-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-methoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2-aza-8-azoniaspiro[4.5]decane;8-[(2R)-2-ethoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-[(2R)-2-methoxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-8-[(3-oxo-3,6,8,9-tetrahydro-1H-furo[3,4-f]isochromen-6-yl)methyl]-2-aza-8-azoniaspiro[4.5]decane;8-(1-hydroxy-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(cyclopropylamino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-((2,2-difluoroethyl)amino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(cyclobutylamino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(azetidin-1-yl)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-((2-methoxyethyl)amino)-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;3-((1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-(2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decan-8-yl)ethyl)amino)propanenitrile;8-[2-(methylamino)-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(R)-8-(2-amino-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;Methyl{(1R)-1-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)-2-[2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]dec-8-yl]ethyl}carbamate;(R)-N-(1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-(2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decan-8-yl)ethyl)methanesulfonamide;1′-[(2R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-2-oxo-1-(5-oxo-2,5-dihydrofuran-3-yl)-1,2-dihydrospiro[indole-3,4′-piperidinium];3-ethyl-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;3-cyclopropyl-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;3-cyclopropyl-8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(R)-8-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-2-(4-(methoxymethyl)-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(R)-8-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-3-methyl-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one;(R)-8-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-4-methyl-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]dec-3-en-1-one;8-(2-(4-ethyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-hydroxyethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(4-cyclopropyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-hydroxyethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(4-chloro-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-hydroxyethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;8-(2-(4-fluoro-1-oxo-1,3-dihydroisobenzofuran-5-yl)-2-hydroxyethyl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(1R,3′R,5S)-9-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-1′-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-3-oxa-9-azaspiro[bicyclo[3.3.1]nonane-7,3′-pyrrolidin]-2′-one;8-((R)-2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)-6-methoxy-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)-8-(1-hydroxy-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(R)-8-(1-hydroxy-3-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;(S)-8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one;and(R)-8-(1-hydroxy-2-methyl-1-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)propan-2-yl)-2-(4-methyl-5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decan-1-one; or a pharmaceutically acceptable salt thereof.
 9. Themethod of claim 1 further comprising administering an active agentselected from losartan, valsartan, candesartan, olmesartan, telmesartan,eprosartan, irbesartan, amlodipine, alacepril, benazepril, captopril,ceronapril, cilazapril, delapril, enalapril, enalaprilat, fosinopril,imidapril, lisinopril, moveltipril, perindopril, quinapril, ramipril,spirapril, temocapril, trandolapril, amiloride, spironolactone,epleranone, and triamterene, or a pro-drug thereof, or apharmaceutically acceptable salt of any of the foregoing.
 10. A methodfor inhibiting ROMK in a patient comprising administering to the patienta ROMK-inhibitory effective amount of a compound having structuralFormula I

or a pharmaceutically acceptable salt thereof wherein: R¹ is —H, halo,—OH, or —OC₁₋₃alkyl; m is an integer selected from zero (R^(3b) isabsent) and 1 (R^(3b) is present); n is an integer selected from 1 or 2;R² is independently selected at each occurrence from —H, ═O (oxo), —OH,—C₁₋₃alkyl or —OC₁₋₃alkyl, provided that when n is 2, then at least oneR² is —H; R^(3a) is —H, ═O —C₃₋₄cycloalkyl or —C₁₋₃alkyl optionallysubstituted with —OCH₃ or 1 to 3 of —F, provided that only one of R² orR³a can be ═O, R^(3b is —H or —C) ₁₋₃alkyl, or R^(3b) is absent whenR^(3a) is ═O or when the dashed bond is a double bond or an aromaticbond; R⁴ is —H or ═O; R⁵ is (a) —H, (b) halo, (c) —C₁₋₃alkyl optionallysubstituted with —O—C₁₋₃alkyl, (d) —C₃₋₆cycloalkyl or (e) heterocycleoptionally substituted with —C₁₋₃alkyl or halo; R⁶ is —H or —C₁₋₃alkyl;R^(7a) is —H or —C₁₋₃alkyl optionally substituted with —OH, —OCH₃ or 1to 3 of —F; R^(7b) is —H or —C₁₋₃alkyl; R⁸ is —H, halo or —C₁₋₃alkyl; R⁹is —H, —F, —OH, —OC₁₋₃alkyl, —CH₂OH, —NH—R¹³ or

R¹⁰ is —H, halo, —CN, —C₃₋₄cycloalkyl, or —C₁₋₃alkyl optionallysubstituted with 1 to 3 of —F; or R⁹ is —O— and is joined together withR¹⁰ to represent—CH₂—CH₂—O—; R¹¹ is —H, —CH₂OH, —CH₂OCH₃, or—C₁₋₃alkyloptionally substituted with 1 to 3 of —F; R¹² is —H, —CH₂OH, —CH₂OCH₃,or—C₁₋₃alkyl optionally substituted with 1 to 3 of —F; or R¹¹ and R¹²are joined together to represent —CH₂—CH₂—, —CH₂—N(CH₃)—CH₂— or—CH₂OCH₂—; R¹³ is —H, —(CH₂)₀₋₂—C₃₋₆cycloalkyl,—(CH₂)₁₋₂—OC₃₋₆cycloalkyl, —(CH₂)₁₋₂—OC ₁₋₃alkyl, —(CH₂)₁₋₂—CN,—C(O)OC¹⁻³alkyl, —SO₂CH₃ or —C₁₋₃alkyl optionally substituted with oneto three of —F; and the dashed bond (“- - -”) represents a single,double or aromatic bond, provided that (A) when n is 2, then the dashedbond is a single bond and m is 1; and (B) when n is 1 and (i) m is 1, or(ii) R^(3a) is ═O and m is zero, then the dashed bond is a single bond;and (C) when n is 1, m is zero, R² is not ═O and R^(3a) is not ═O, thenthe dashed bond is a double bond to a patient in need thereof.
 11. Themethod of claim 1 wherein the disorder is selected from hypertension orheart failure.
 12. A method for causing diueresis, natriuresis or both,in a patient in need thereof by administering to the patient atherapeutically effective amount of a compound having structural FormulaI

or a pharmaceutically acceptable salt thereof wherein: R¹ is —H, halo,—OH, or —OC₁₋₃alkyl; m is an integer selected from zero (R³b is absent)and 1 (R³b is present); n is an integer selected from 1 or 2; R² isindependently selected at each occurrence from —H, ═O (oxo), —OH,—C₁₋₃alkyl or —OC₁₋₃alkyl, provided that when n is 2, then at least oneR² is —H; R^(3a) is —H, ═O, —C₃₋₄ cycloalkyl or —C₁₋₃alkyl optionallysubstituted with —OCH₃ or 1 to 3 of —F, provided that only one of R² orR^(3a) can be ═O, R^(3b) is —H or —C₁₋₃alkyl, or R^(3b) is absent whenR^(3a) is ═O or when the dashed bond is a double bond or an aromaticbond; R⁴ is —H or ═O; R⁵ is (a) —H, (b) halo, (c) —C₁₋₃alkyl optionallysubstituted with —O—C₁₋₃alkyl, (d) —C₃₋₆cycloalkyl or (e) heterocycleoptionally substituted with —C₁₋₃alkyl or halo; R⁶ is —H or —C₁₋₃alkyl;R⁷a is —H or —C₁₋₃alkyl optionally substituted with —OH, —OCH₃ or 1 to 3of —F; R^(7b) is —H or —C₁₋₃alkyl; R⁸ is —H, halo or —C₁₋₃alkyl; R⁹ is—H, —F, —OH, —OC₁₋₃alkyl, —CH₂OH, —NH—R¹³ or

R¹⁰ is —H, halo, —CN, —C₃₋₄cycloalkyl, or —C₁₋₃alkyl optionallysubstituted with 1 to 3 of —F; or R⁹ is —O— and is joined together withR^(1O) to represent—CH₂—CH₂—O—; R¹¹ is —H, —CH_(2OH, —CH) _(2OCH) ₃, or—C₁₋₃alkyl optionally substituted with 1 to 3 of —F; R¹² is —H,—CH_(2OH, —CH) _(2OCH) ₃, or —C₁₋₃alkyl optionally substituted with 1 to3 of —F; or R¹¹ and R¹² are joined together to represent—CH₂-CH₂—,—CH₂—N(CH₃)—CH₂— or —CH₂OCH₂—; R¹³ is —H,—(CH₂)₀₋₂—C₃₋₆cycloalkyl, —(CH₂) ₁₋₂—O C₃₋₆cycloalkyl, —(CH₂)₁₋₂—OC₁₋₃alkyl, —(CH₂)₁₋₂—CN, —C(O)OC₁₋₃alkyl, —SO₂CH₃ or —C₁₋₃alkyloptionally substituted with one to three of —F; and the dashed bond(“- - -”) represents a single, double or aromatic bond, provided that(A) when n is 2, then the dashed bond is a single bond and m is 1; and(B) when n is 1 and (i) m is 1, or (ii) R^(3a) is ═O and m is zero, thenthe dashed bond is a single bond; and (C) when n is 1, m is zero, R² isnot ═O and R^(3a) is not ═O, then the dashed bond is a double bond.